Certified Wireless USB from the USB-IF

With more than 2 billion legacy wired USB connections in the world today, USB is the de facto standard in the personal computing industry. Soon, these same, fast, interoperable connections will become available in the wireless world, with the introduction of Certified Wireless USB from the USB-IF. Certified Wireless USB is the new wireless extension to USB that combines the speed and security of wired technology with the ease-of-use of wireless technology. Wireless connectivity has enabled a mobile lifestyle filled with conveniences for mobile computing users. Certified Wireless USB will support robust high-speed wireless connectivity by utilizing the common WiMedia MB-OFDM Ultra-wideband (UWB) radio platform as developed by the WiMedia Alliance.

UWB technology offers a solution for high bandwidth, low cost, low power consumption, and physical size requirements of next-generation consumer electronic devices.

Certified Wireless USB is the first high-speed wireless personal interconnect technology to meet the needs of multimedia consumer electronics, PC peripherals, and mobile devices.

Certified Wireless USB will preserve the functionality of wired USB while also unwiring the cable connection and providing enhanced support for streaming media CE devices and peripherals.

Certified Wireless USB performance is targeted at 480Mbps at 3 meters and 110Mbps at 10 meters.

Wireless USB Compliance Testing

Download and review the USB-IF Wireless USB Certification Procedures
Download and review the test specifications and test tools, and pre-test your products
Fill out the Wireless USB Certification Lab visit request form (optional)
Complete the Wireless USB product checklist and submit to the USB-IF
Compliant products will be posted to the USB-IF Integrators List

Is dynamic WEP supported?

According to this article:
http://www.oreillynet.com/pub/wlg/4598
the «popular Hermes-based Orinoco 802.11b cards» don't have driver support
for dynamic keys.

On the other hand, the "802.1X Port-Based Authentication HOWTO" says:
«Many drivers developed outside the kernel, however, support for dynamic
WEP; HostAP, madwifi, Orinoco, and atmel should work without problems.»
(http://oreilly.linux.com/howtos/8021X-HOWTO/dynwep.shtml)

Who is right?
I have searched the Linux ORiNOCO Driver website and it's mailing lists and
I have not found a sinle reference to dynamic WEP. Am I blind or is this a
too esoteric feature for orinoco card users?

Is Dynamic WEP Secure Enough enterprise solution ?

Dynamic WEP refers to the combination of 802.1x technology and the EAP. EAP is a flexible Layer 2 authentication protocol and a replacement to PAP and CHAP under Point-to-Point Protocol (PPP). The term dynamic WEP is derived from its unique ability to change (rekey) encryption keys. This prevents an attacker from being able to collect enough data to crack the current encryption keys. Each time a user logs into the network, a new key is created for that session. No other user will have the same session key, and the key lengths are such that reuse of the keys would be impossible to predict. Dynamic WEP also initiates more frequent key updates during the user's session, constantly changing the user's key by periodically renewing the keys every few minutes. This prevents an attacker from capturing significant data with the same key, thereby preventing any meaningful decryption of the WEP key. 

The argument of secure environment using Dynamic WEP comes from the original post written by Mr. Shankar. I forgot the original link which linked back to his original post.

We have all considered how insecure Wireless is using dynamic WEP in the scenario mentioned and I quote - "Due to one of our applications, we will be sending a clear strong signal to the parking lot". As also the mail says "Right now my plan is use PEAP w MSCHAP v2 with dynamic WEP crypto for my corporate SSID" to quote from the mails of Rocko.

My understanding of Dynamic WEP is that, in the case of PEAP or for that matter any other form of EAP derived security, there is no single common WEP key that is derived and used for all the clients. The point I am trying to lay my stress on is "no single common WEP key". In this scenario - if we were to look at this organization where we assume, should I say about 100 Wireless clients, then at an average of 15 people under each Access Point, this translates to 15 different keys - one key per person on the same Access Point. Add to this the probability of people moving from one Access Point to another at every (say) 3hours interval. Add to that the probability that the keys are not all changing at a defined point in time - this implies that based on when the user has derived the first dynamic key - the key changes at configured intervals.

To an external user (sitting in the parking lot) this poses 5 levels of randomness -

1. different users have different keys
2. different users changing their keys at different points in time
3. different users traversing across Access Points and hence changing their keys
4. The physical security that is existing on the ground that can contribute (if not greatly - at least to a reasonable extent) and hence the probability of finding out a parking lot hacker
5. Add again the probability of this guy getting sufficient numbers of weak IV's

Add to this, the number of users that are really sitting down in an area that provides a strong signal to the parking lot. Add also "direction finding capabilities" - (I am not too sure what this direction finding capability of the Access Point is, but based on context I guess it is something that deals with improving security).

SHOULD WE STILL BE AS PARANOID AS THESE MAILS SOUND OR CAN WE RELAX A BIT.

Ofcourse I would also like to add that we have not looked at whether this is a scenario where we have a Patch Antenna/ Parabolic Antenna that transmits signals in a defined direction - in this scenario there is a possibility of the replies above being used as an effective hack

Moreover, most Organizations that have this level of consideration for security should be having some form of IDS/ IPS - NIDS/ HIDS - wouldn't these have detected/ alarmed the Admin in some way or the other if he is on the LAN/ some Server/ workstation

Technically, if we were to sit down in front of a box, it will crack after sometime, but realistically in the scenario - is this possible, I guess this is the outlook that we should take when we discuss on such problems. Moreover, this immediately puts a doubt in the mind of the person about PEAP and EAP related security measures or for that matter any solution when thought from this point angle


I WOULD LIKE TO KNOW THE COMMUNITIES' VIEW IN THIS SCENARIO.

Securing Wireless LANs with PEAP and Passwords

The wireless local area network (WLAN) solution described in this documentation works equally well with either dynamic Wired Equivalent Privacy (WEP) or Wi-Fi Protected Access (WPA) WLAN protection. The implementation differences between the two are minor and are documented in this appendix.

Currently, there are some potential difficulties with using WPA, which include:

• Manual configuration of WPA settings: The support for setting Windows XP client WPA settings using group policy is not available in the versions of Windows earlier than Windows Server™ 2003 Service Pack 1. Until Service Pack 1 is available and you have deployed it in your organization, you will have to configure your clients manually (there is no way to script WLAN settings for Windows XP). You need to install Service Pack 1 only on the server on which you are editing the WLAN settings Group Policy object (GPO); it is not required on the clients, domain controllers, or IAS servers.

• Restricted availability of WLAN clients: At the time of writing, Microsoft only provides WPA support for Windows XP Service Pack 1 and later.

• Availability of WPA compliant hardware: Although WPA support is now mandatory for all Wi-Fi certified hardware, existing network equipment may need to be upgraded to support WPA. You will need to obtain firmware updates for any access points or network adapters that do not currently support WPA. In some (rare) cases, you may need to replace equipment if the manufacturer does not produce WPA updates.


Using WPA in Place of WEP
Although the majority of the guide is applicable to both WPA and dynamic WEP, there are two main points in the documentation where the instructions differ:

• The “Creating an IAS Remote Access Policy for WLAN” section in Chapter 5, “Building the Wireless LAN Security Infrastructure.”

• The “Creating the WLAN Settings GPO” section in Chapter 6, “Configuring the Wireless LAN Clients.”


Creating an IAS Remote Access Policy for WLAN with WPA
To use WPA WLAN protection in place of dynamic WEP, you should set the client session time–out value to 8 hours instead of 60 minutes. WPA has an in–built mechanism to generate new WLAN encryption keys, so it does not need to force the clients to re–authenticate frequently. Eight hours is a reasonable value to ensure that clients have valid up–to–date credentials (for example, it ensures that a client cannot remain connected for excessive periods after its account has been disabled). In very high security environments, you can reduce this time–out value, if needed.

In the "Modifying the WLAN Access Policy Profile Settings" section in Chapter 5, “Building the Wireless LAN Security Infrastructure,” use the following procedure to set the remote access policy profile settings:

To modify wireless access policy profile settings:

1. In the Internet Authentication Service MMC, open the properties of the Allow Wireless LAN Access policy, and then click Edit Profile.

2. On the Dial-in Contraints tab, in the Minutes clients can be connected (Session-Timeout) field, type the value 480 (480 minutes or 8hours).

3. On the Advanced tab, add the Ignore-User-Dialin-Properties attribute, set it to True, and then add the Termination-Action attribute and set it to RADIUS Request.


You also need to change the session time–out in the wireless access point (AP) to match (or exceed) the time–out value set in this procedure.

Manually Configuring Windows XP WLAN Settings for WPA
Until GPO support becomes available in Windows Server 2003 Service Pack 1, you must configure WPA settings on the client manually. WPA is supported on Windows XP Service Pack 1 with the WPA client download installed (or on Windows XP Service Pack 2).

Note: When GPO support becomes available, you can also use the following procedure to create a Wireless Network Policy using the same settings.

To manually configure WPA WLAN settings:

1. Open the properties of the Wireless Network interface. If the WLAN is displayed in the Available Networks list, select it, and click Configure..., otherwise click Add (in the Preferred Networks section).

2. Type the WLAN name into the Network Name (SSID) field (if it is not already displayed there) and, in the Description field, enter a description of the network.

Note: If you have an existing WLAN and you intend to run this side–by–side with the 802.1X–based WLAN of this solution, you must use a different Service Set Identifier (SSID) for the new WLAN. This new SSID should then be used here.

3. In the Wireless Network Key section, select WPA (not WPA PSK) as the Network Authentication type and TKIP as the Data Encryption type. (If your hardware supports it, you can choose the higher strength Advanced Encryption Standard (AES) in place of TKIP).

4. Click the IEEE 802.1x tab, and select Protected EAP (PEAP) from the EAP Type drop–down list.

5. Click the Settings... button to modify the PEAP settings. From the Trusted Root Certificate Authorities list, select the root CA certificate for the CA. (This is the CA that you installed to issue IAS server certificates—see Chapter 4 for more details).

Important: If you ever need to re–install your CA from scratch (not just restore from backup), you will need to edit the client settings and select the root CA certificate for the new CA.

6. Ensure that Secured Password (EAP-MS-CHAP v2) is selected in the Select Authentication Method and check the Enable Fast Reconnect option.

7. Close each properties window by clicking OK.


Configuring Pocket PC 2003 for WPA
WPA was not supported natively in Pocket PC 2003 at the time of writing; however, this may be implemented in the future. Support for WPA on Pocket PC may also be available from other vendors.

Migrating from WEP to WPA
If you have deployed a secure WLAN solution based on dynamic WEP and want to migrate to WPA, you need to follow the steps in this section. You must ensure that you have deployed WPA software support (for example, the Windows XP WPA component) and hardware support (AP firmware and network adapter driver updates) prior to the migration. References in this procedure to configuring WPA settings in GPOs are only valid when the GPO is edited from Windows Server 2003 Service Pack 1 or later. This service pack had not been released at the time of writing. If you are not using Windows Server 2003 Service Pack 1 or later, follow the instructions given in the “Manually Configuring Windows XP WLAN Settings” section in this appendix.

To migrate from WEP to WPA, if your APs support dynamic WEP and WPA simultaneously:

1. Configure all wireless APs to support both dynamic WEP and WPA.

2. Create a new WLAN client settings GPO. Create a Wireless Network policy that configures the correct settings for WPA (refer to the procedure provided in the "Manually Configuring Windows XP WLAN Settings" section in this appendix). Then disable the existing WEP GPO and enable the WPA GPO so that all WPA settings are sent out to all clients. The clients will start using WPA on the WLAN following the next GPO refresh.

Note: If you are configuring your clients manually, you must disable the GPO that contains the WEP settings; if you do not do this, the manual WPA settings will be overwritten by the GPO.

3. Finally, you should update the IAS remote access policy session time–out and the client session time–out in the AP (as described in the "IAS Remote Access Policy" section earlier in this appendix).

To migrate from WEP to WPA, if your APs do not support simultaneous use of WEP and WPA:

1. Create a new WLAN SSID for the WPA network.

2. Edit the client network settings GPO and add the new SSID using WPA parameters (as described in the "Manually Configuring Windows XP WLAN Settings" section earlier in this appendix). If you are configuring your clients manually, you should configure them with the new SSID and WPA settings for that SSID. Do not remove the settings for the old WEP SSID in either case.

3. Working site–by–site, reconfigure your APs from WEP to WPA support, changing the SSID of the AP. As you reconfigure each AP, the clients will switch to the new SSID and use WPA.

4. Once you have reconfigured all APs, you can update the remote access policies on all IAS servers. You need to increase the session time–out value in the remote access policy (from 60 minutes to 8 hours) and change the same setting in the wireless APs (as described in the "IAS Remote Access Policy" section in this appendix).

5. Once the migration is complete, you can remove the WEP SSID from the GPO.


References
This section provides references to important supplementary information or other background material relevant to this appendix.

• The Cable Guy — March 2003, Wi-Fi Protected Access™ (WPA) Overview, available at the following URL:

http://www.microsoft.com/technet/community/columns/
cableguy/cg0303.mspx

• Microsoft Knowledge Base Article 815485, "Overview of the WPA Wireless Security Update in Windows XP," available at the following URL:

http://support.microsoft.com/?kbid=815485

• Microsoft Press Pass Announcement on WPA Availability, available at the following URL:

http://www.microsoft.com/presspass/press/2003/mar03/03-31WiFiProtectedAccessPR.mspx

• "Wireless 802.11 Security with Windows XP" white paper available at the following URL:

http://www.microsoft.com/windowsxp/pro/techinfo/
administration/wirelesssecurity/

Hack most wireless LANs in minutes!

by: George Ou

Even after two years of WPA certification and nearly one year after 802.11i ratification, you might be wondering why I’m still talking about WEP encryption. The fact is, I would love to stop talking about it if there weren’t such an overwhelming percentage of corporations, retail outlets, and hospitals still using WEP. Although WPA brought us TKIP (think of TKIP as WEP 2.0) encryption and 802.11i brought us AES encryption, the upgrade process has been extremely painful and many products still don’t support TKIP let alone AES. The sad state of wireless LAN security is that the majority of corporations and hospitals still use dynamic per-user, per-session WEP keys while the majority of retail outlets that I’ve seen still use a single, fixed WEP key.

In the past, a hacker was at the mercy of waiting long periods of time for legitimate traffic on a wireless LAN to collect 10 million of packets to break a WEP key. In my previous blog on this topic, which was based on Mike Ossmann’s WEP article, I alerted you to the startling fact that even wireless LANs that used 802.1x/EAP authentication to dynamically assign unique per-user, per-session WEP keys were no longer safe against WEP hacking since WEP cryptanalysis had improved 50 fold. Instead of waiting for hours or even days for those 10 million packets, you now only needed about 200,000 packets to break WEP. Even though dynamic WEP key rotation could change a user’s WEP key every few minutes or so (note that key rotation isn’t always implemented by default), the new WEP cryptanalysis techniques put even dynamic WEP in striking range. Now with the new active attacks on WEP described in Ossmann’s follow-up article, hackers no longer need to passively wait for legitimate packets on a wireless LAN because they can actively inject packets into a wireless LAN to ensure a speedy packet collection session. The end result is, any WEP based network with or without Dynamic WEP keys can now be cracked in minutes! If you’re scared, you should be and you’d better go back and read the recommendations in the end of my previous blog if you’re still running WEP in any form.

Using an Unsecured Wireless Network

A reader recently asked about the risks of using open public WiFi hotspots. These links show as "unsecured wireless connections" on your Windows laptop. Is it safe to use your credit card over such connections? Are there any precautions to take to make your connection more secure?
When using an https:// connection through your Web browser, your personal information is protected, even on otherwise insecure connections. This is generally considered strong enough network security to have when sending your credit card number, for example. At a public hotspot, the greater risk is usually someone situated behind you able to see the numbers you type.

Another security risk on public hotpots involves other computers also connected to this unsecured network. Network attacks can be made through them, by connecting to your computer and possibly downloading information from your hard drive.

People address this latter problem by running a firewall program on their computer. Firewalls guard against these incoming attackers. It is additional considered good practice not to stay connected to unsecured networks for too long of a time to become an attack target. You should always run a good firewall program whenever connected to a "unsecured wireless network" and disconnect when not using your link.

What is infrastructure mode in wireless networking?

Infrastructure mode wireless networking bridges (joins) a wireless network to a wired Ethernet network. Infrastructure mode wireless also supports central connection points for WLAN clients.

A wireless access point (AP) is required for infrastructure mode wireless networking. To join the WLAN, the AP and all wireless clients must be configured to use the same SSID. The AP is then cabled to the wired network to allow wireless clients access to, for example, Internet connections or printers. Additional APs can be added to the WLAN to increase the reach of the infrastructure and support any number of wireless clients.

Compared to the alternative, ad-hoc wireless networks, infrastructure mode networks offer the advantage of scalability, centralized security management and improved reach.

The disadvantage of infrastructure wireless networks is simply the additional cost to purchase AP hardware.

Note that home wireless routers all feature a built-in AP to support infrastructure mode.

WiMAX expected to supercharge wireless applications

By Colin Gibbs

WiMAX could be the technology that fuels the fusion of all sorts of mobile applications, integrating video, location-based services and a host of other offerings.

And analysts generally agree that speedy access to the wireless Web will be the key.

“When I talk WiMAX, I always quote my boss Sean Maloney,” said Ron Peck of Intel Corp., referring to the company’s general manager of sales and marketing. “If you’re pitching WiMAX, you must repeat: the mobile Internet is the next big thing.”

It’s no secret that WiMAX offers a combination of wide coverage, high capacity and low latency rarely seen—if not unprecedented—in wireless. The technology is claimed to top out at 70 megabits per second and delivers a footprint of as many as 37 miles under ideal conditions (although not simultaneously—like DSL, the network’s speed is influenced by its reach, and vice versa).

Actual network speeds are likely to average between 2 and 4 Mbps, according to operators. But even on the low end, WiMAX appears to be speedier and offer more capacity than 3G networks.

Fat pipe for hungry users

That combination means more than just connecting lots of users more efficiently, according to Daryl Schoolar, a senior analyst with In-Stat. It means more consumers can consume more data, more quickly.

“From everything I’ve been told by vendors who make both WiMAX and cellular equipment, WiMAX has significantly lower lag,” said Schoolar. “They also tell me it can support more connected users. That would certainly lend itself toward real-time apps such as streaming apps.”Which is why WiMAX is expected to give birth to a host of connected devices dedicated to a single use. Not only is the technology likely to serve as a catalyst for the production of mobile music and video players, it will provide connectivity to consumer electronics such as cameras, camcorders and gaming devices—devices that don’t traditionally offer network access.

Taking advantage of WiMAX

But even as it sparks an increase in the number of dedicated devices, WiMAX is predicted to provide a boost to converged devices. Just as 3G networks and GPS technology has provided a platform for developers to build compelling applications that deliver both relatively low latency and remarkably accurate location information, WiMAX’s speed and capacity could prove ideal for offerings that fuse a number of different applications.

“I think you’re going to see a lot of the video side of the Internet,” said Peck, including video-sharing and other mobile social networking features. “I also think you’re going to see a ton of visual apps” that integrate video with location-aware applications, games and other offerings.

Other possibilities include teleconferences that include both video and Web-based applications, and multiplayer games that feature GPS location information and nearly real-time play.

And while WiMAX may suffer in urban environments—where indoor usage may slow the network to the lower range of expected speeds even when a tower is relatively nearby—the technology will work hand-in-hand with Wi-Fi and other channels of connectivity, Peck said.

Questioning Wi-Fi

Wi-Fi is “stupid,” according to Peck, and simply offers a connection without taking other technologies into account. But WiMAX is “very smart” and can hand users off if a more efficient network is available. So consumers could surf the Web or sit in on a multiplayer gaming session on WiMAX on the commute home, then automatically switch to Wi-Fi when they get indoors.

So the new technology may provide a platform that not only serves as a high-speed highway, it will allow devices to take detours whenever backups occur. Developers will scramble to leverage WiMAX, Peck predicted, throwing all sorts of applications at the wall to see what sticks.

“I think it’s going to be the wild, wild West,” Peck predicted.

Big players have big plans for WiMAX

By Kelly Hill

Consider WiMAX a bit schizophrenic. The technology is taking two divergent paths as different countries and different companies explore how best to put it to use in their respective markets.

Dr. Mohammad Shakouri, board member and VP of marketing for the WiMAX Forum, has described the technology as serving “the richest of the rich and the poorest of the poor” as companies lay out strategies that include either a high-end focused, consumer electronics play or a wireless broadband provider for the masses and in rural areas.

Both strategies are playing out in the U.S. market, but the space is dominated by three major players with large spectrum holdings in the 2.3 GHz and 2.5 GHz bands: AT&T Inc., Clearwire Corp. and Sprint Nextel Corp.

Sprint Nextel and Clearwire have been overshadowing the conversation of late, first appearing to operate on separate tracks and then announcing a partnership that is supposed to speed the deployment of mobile WiMAX as well as ease the burden of network costs for each respective company. The corporations have outlined a plan in which Sprint Nextel will build out 70% of the initial 100 million potential customers to be covered, while Clearwire builds out 30%. Sprint Nextel has outlined plans for a wide variety of consumer electronic devices to make use of the new network and also hinted at allowing wholesale agreements that could boost WiMAX traffic.

Sprint Nextel’s bet

Sprint Nextel has been outpaced in the traditional wireless market by Verizon Wireless and AT&T Mobility in subscriber growth and customer metrics, and it is betting that changing the nature of the competition will give it an advantage.

“It’s very difficult to change the balance of the subscriber bases right now in the U.S.,” said Moe Tanabian, analyst with IBB. Given Sprint Nextel’s customer and financial issues, he said, “they have to do something drastic. … They’re relying on this assumption—it may turn out to be true—that we’re moving from voice-centric wireless consumption to a data-centric wireless consumption” during the next three to five years.

Tanabian noted that Sprint Nextel first began its WiMAX push by aggressively talking up the technology and laying out ambitious plans—and that it has since toned down its approach a bit.

“They started to see things are not as rosy as they thought,” Tanabian said—and that led to the choice of Clearwire as a partner for WiMAX. The two companies plan to cooperate on services and branding under the Xohm brand name.

Clearwire’s upward mobility

For Clearwire, meanwhile, the announcement of the Sprint Nextel deal has catapulted it from an untried, small competitor into one that can play in the ranks of the top four wireless operators. It opens up the ability for the company to reach a vast potential customer base of 100 million people and to augment its coverage initially through use of Sprint Nextel’s cellular network.

Tanabian also noted that the company recently announced distribution agreements with satellite television providers DirecTV Group Inc. and EchoStar Communications Corp. that would enable it to fashion a triple-play bundle of services.

“They’re trying to diversify their business model,” Tanabian said. “So if for whatever reason the device ecosystem doesn’t develop as fast as they think it will, they still have other means of forging a business.

“Clearly, Clearwire was the winner from this deal—although Sprint won as well, by turning a foe into a friend and just getting rid of that headache. But Clearwire, it was just pure, sweet sugar for them.”

AT&T in Alaska

AT&T declined to speak about its plans for its holdings in the 2.3 GHz bands. However, the company did issue a statement on its strategy related to WiMAX, noting its deployment this summer in Alaska and apparently taking the path of using WiMAX to extend broadband coverage rather than push new technology.

“AT&T has been heavily involved in the development of emerging technologies like WiMAX and Wi-Fi mesh networks, which bring strong potential for extending and expanding customers’ ability to access broadband connections. The company has played a leading role in development of emerging WiMAX standards, and has launched 22 limited deployments and trials of WiMAX and other fixed wireless technologies to date, eight of which remain in operation as commercial offerings today,” said AT&T spokeswoman Jenny Parker.

Parker added that AT&T Alascom had announced its latest deployment of WiMAX in Juneau, Ala., in July and that it “plans to deploy WiMAX-based broadband in additional Alaska markets in 2008.”

“Outside of Alaska, AT&T will evaluate further opportunities to deploy WiMAX and other fixed wireless technologies based on customer needs and the results of its existing technical and commercial deployments,” Parker said.

Those opportunities could also include the bucket of 700 MHz spectrum AT&T Mobility recently acquired from Aloha Partners L.P. for $2.5 billion. The spectrum, which is near the 700 MHz spectrum the government is scheduled to begin auctioning early next year, gives the industry’s No. 1 player a deeper spectrum portfolio covering nearly 200 million potential customers across the country.

The carrier said it has yet to decide how to use the spectrum, but with its enviable propagation characteristics, you can bet it will be for an important service.

“We’ll use the spectrum either for broadcast mobile or two-way voice and data services, but not both,” AT&T Mobility spokesman Michael Coe recently said. “We’ll make that determination based on what’s best for our customers.”

Ready to Pull the Plug?

The advantages of a local area network (LAN) are obvious: Users can share software applications and data—in short, they can stay in touch. Equally obvious are its disadvantages: Each computer—even an otherwise portable laptop—must be tethered by cable to a port in the wall. Unplug and you’re offline and out of touch.

THE SPEED ISSUE

In the past, speed was not wireless’ strong suit, so potential users will want to know: Is a WLAN fast enough for our needs? A typical wired LAN transmits data at between 10 and 100 megabits per second (Mbps). The old wireless LANs (based on the 802.11 technical standard for wireless transmission) crept along at no more than 2 Mbps, which is why most users rejected WLANs unless they had no other choice. Now a new standard (802.11b) is able to move data at more than an order of magnitude faster—a speed that makes it nearly as fast as the lower end of the standard LAN transmission rate, and thus a practical choice for most business environments.

Compared with LAN hardware, WLAN equipment is relatively expensive (we’ll break down costs later in this article). However, when you factor in WLANs’ many savings—which we’ll also outline—the entire setup works out to be less expensive. Here’s why: The biggest single expense of a traditional LAN is the cost of installing it. Wires or cables have to be snaked under floors and through ceilings and walls, and ports must be installed for each computer hook-up. When an office is reconfigured, new cable usually has to be added and new ports installed so users can plug in. Those costs typically amount to several times the cost of the LAN equipment itself.

With a wireless system, however, you avoid all those structural installation costs because there’s no need to run wires or cable to each port—transmission is through the air. Since floors, ceilings and walls are transparent to radio waves, the signals go right through them. And since WLAN software is mostly plug-and-play capable, much of it loads onto the computer network automatically, requiring little customization.

In addition, because WLANs don’t need structural installation, moving the computer setup to a new office space is as simple as packing up the equipment, then unpacking it in the new location and plugging it into the electric wall socket. No walls or floors to open up, no cables, wires or ports to install. Even upgrades or office expansions are relatively easy because there is no need to replace or move anything structurally.

From a productivity point of view, WLANs are especially attractive. If the computer users in the office all work on laptops—recommended in a wireless office—they can stay connected no matter where in the area they tote their computers (or PDAs or handhelds). All the computers need are wireless network interface cards (NICs). That gives them full access to the files on the network, printers and the Internet. A WLAN with sufficient, properly positioned access points can provide wireless connectivity over an entire building or even over an office complex.

WORKING TOGETHER

When used in an audit or consulting engagement, WLANs really shine. For example, the auditors can take their laptops with them and

Share disk storage on the senior auditor’s laptop, making many hard-copy workpapers unnecessary.

Access special application software designed for networks or collaborative workgroup projects, making the engagement more efficient.

Link to a client’s system more easily, enabling the use of client resources, including disk access for file downloads and fast Internet access.

When used in conferences, meetings and training programs, a wireless system makes it easier to display multimedia presentations, technical documents, training exercises and other materials directly on the participants’ computers. A wireless setup could replace expensive multimedia projectors, which cost a minimum of about $4,000 each.

The bottom line: The cost of installing a WLAN varies considerably. Much depends on the organization’s current computer equipment, the wireless hardware selected, the vendor, the physical proximity of the computers, the number of staff members who access the system and whether and how much professional assistance is needed to get the system up and running.

Proper positioning of access points is critical to achieve optimal communications; fortunately, several vendors bundle system survey tools to determine the best positions with their equipment. In general, equipment designed for enterprise-wide wireless networking is more expensive because the equipment and bundled software are more sophisticated than that designed for small office use. However, prices have been dropping recently.

CALCULATE COSTS

The following provides a minimum and maximum cost estimate of the equipment that is needed for a WLAN in a typical office:

Generally, every staff person who must move about the office with his or her computer should have a laptop that can accommodate a wireless NIC. A good quality laptop costs between $2,000 and $3,500.

Every laptop needs a wireless NIC, which costs between $100 and $300.

Every desktop to be connected to the WLAN will require adapters (a PCI or ISA) and a wireless NIC, which costs between $160 and $400. At least one desktop unit should act as a file and print server.

Wireless LAN signals have a transmission range of 80 to 1,500 feet, depending on the type of equipment, the data exchange rate and the obstacles that the signals must pass through. Access points also vary by the maximum number of simultaneous users, ranging from 15 to 60 users per access point depending on the type of equipment.

For optimal positioning of access points, it’s probably wise to engage a consultant to conduct signal testing. In general, you’ll probably need an access point for every 2,000 square feet of floor space. Access points cost between $200 and $1,500.

You should also add between $200 and $1,000 for a firewall or cable/DSL router.

These estimates don’t include training staff members, obtaining professional assistance in installation, special-purpose network software to increase staff productivity, fees charged by the Internet provider, network administration and maintenance.

Although security problems exist with any type of network, WLANs are slightly more risky than traditional LANs. The new 802.11b standard includes built-in security, providing some defense against unauthorized interception and access; however, there still are weaknesses. To upgrade security, some developers have implemented proprietary solutions; unfortunately, these features may make it impossible to interchange equipment from different manufacturers, limiting your LAN design options. But, as a practical matter, most users probably should not worry about security unless they feel that their size or type of business make them high-risk targets.

Should you consider unplugging and going to a WLAN? That depends on many factors. If you must upgrade your conventional wired LAN, and that work involves new wires or cables, you may want to unplug because in the long run it will probably save you money.

One thing you can be assured of is that wireless technology is the wave of the future—or at least the immediate future. While the hardware today is a bit pricey, costs are falling and will continue to do so for some time to come, and speed and reliability will improve apace. Since WLAN installations do not require structural work, it may be cheaper to unplug now and upgrade over time as WLAN hardware improves rather than make a huge investment in new cables and wires.

CROSS-LAYER WIRELESS MULTIMEDIA TRANSMISSION:

BRIEF REVIEW OF ADAPTATION AND PROTECTION STRATEGIES AT DIFFERENT LAYERS

Numerous solutions have been proposed for efficient multimedia streaming over wireless networks. Potential solutions for robust wireless multimedia transmission over error-prone networks include application-layer packetization, (rate-distortion optimized) scheduling, joint source-channel coding, error resilience, and error concealment mechanisms. An excellent review of channel-adaptive multimedia streaming research is provided in.

Transport issues for wireless (multimedia) transmission have been examined in. At the PHY and MAC layers, significant gains have been reported by adopting cross-layer optimization, such as link adaptation, channelaware scheduling, and optimal power control. However, these contributions are aimed at improving throughput or reducing power consumption without taking into consideration multimedia content and traffic characteristics. Explicit consideration of multimedia characteristics and requirements can further enhance the important advances achieved in cross-layer design at the lower layers. Possible solutions and architectures for cross-layer optimized multimedia transmission have been proposed in.

To provide QoS for multimedia applications, the IEEE 802.11 Working Group has currently defined a new supplement to the existing legacy 802.11 MAC sublayer, called IEEE 802.11e. Note that even though emerging MAC standards provide QoS support, there are no QoS guarantees for multimedia applications, and systemwide resource management is not always fair or efficient. This is due to the time-varying nature of the wireless channel and multimedia characteristics, and also the lack of cross-layer awareness of the application and MAC layers about each other.

WiMAX today and tomorrow

WiMAX today

Despite the all-round occurrence of the WiMAX still in the design even in the most developed countries, introduction of the standard is progressing at an enviable pace. Quite recently, last autumn during the days of Intel Developers' Forum in the building of Russian Academy of Sciences the experimental network IEEE802.16-2004 was demonstrated in action. And last week in Kiev, Ukraine, Ukrainian advanced technologies commissioned the first in the ex-USSR network of wireless broadband access to Internet on the base of the WiMAX technology. From that week onwards, the network by "Ukrainian Advanced Technologies" dubbed ALTERNET started rendering services of wireless broadband access to Internet on the base of WiMAX using client devices built on the Intel PRO/Wireless 5116 chipset.

The services are about fixed wireless access to Internet using the WiMAX technology based on the Alvarion client equipment built on the Intel PRO/Wireless 5116 chipset. They are offered to companies and private persons who are based in the areas of poorly developed or outdated cable infrastructure. "Ukrainian Advanced Technologies" intends to provide its services on a turn-key basis in merely two days after the first customer's call. Today, you can subscribe to the services in Kiev and Kharkov. There are plans for the first quarter of the next year to establish regional offices to render the access services in Dnepropetrovsk, Odessa, Donetsk, and Lvov. On the whole, it is planned to provide WiMAX connection facilities in all the regional centers of Ukraine by the end of 2006.

In fact, you shouldn't think that some sort of a WiMAX anomaly is going on in the Ukraine. Introduction of WiMAX networks is going on continuously these days, announcements of launching such networks are appearing every day, and only in Russia this issue is being solved extremely slowly (read below).

Modern hardware for WiMAX

As regards the capabilities of PRO/Wireless 5116 chipset officially presented by Intel in April 2005, it proved to be one of the first products in the industry with support for the WiMAX standard. This Intel chipset is made in a 360-pin PBGA casing, offers functionality needed to implement establish economical high-speed wireless modems for the home and office. Solutions based on PRO/Wireless 5116 allow providing broadband access to the Internet in remote areas where no DSL or cable networks are there and establish communication between tasks distributed a few miles apart.

Combined with a RF module and a third-party amplifier, the SoC system Intel PRO/Wireless 5116 with support for IEEE 802.16-2004, formerly known as the Rosedale, provides the possibility to use WiMAX networks for a wide circle of users.. At the same time, the Intel PRO/Wireless 5116 interface supports not only external but internal solutions, e.g. WiMAX subscriber modems and home-based gateways.

Intel PRO/Wireless 5116 (Rosedale)

WiMAX Forum. Intel's role in establishing the standard

For the purposes of testing, standardization, certification and marketing of WiMAX products, the WiMAX Forum industry alliance has been established. It's just this alliance that issues "WiMAX Forum Certified" verdicts. By now, the number of WiMAX Forum members is rapidly approaching to 200, and over one quarter of the number are operators who are rendering provider services based on the WiMAX technology.

Once of the most active member of the WiMAX Forum alliance is Intel who participates in all the undertakings – from problem statement up to the ratification of standards and development of end equipment. Intel is now cooperating with companies who have deployed pre-standardized WiMAX broadband wireless networks in over than 125 countries. They offer a wide range of options - from stationary systems of wireless access up to enterprise-scale point-to-point data transmission systems.

For the purposes of testing, standardization, certification and marketing of WiMAX products, the WiMAX Forum industry alliance has been established. It's just this alliance that issues "WiMAX Forum Certified" verdicts. By now, the number of WiMAX Forum members is rapidly approaching to 200, and over one quarter of the number are operators who are rendering provider services based on the WiMAX technology. Apart from Intel Corporation, other known companies participate in the WiMAX Forum, among them Airspan Networks, Alvarion, Aperto Networks, Ensemble Communications, Fujitsu Microelectronics America, Nokia, OFDM Forum, Proxim Corporation, Wi-LAN Inc. and others.

One of the most active member of the WiMAX Forum alliance is Intel who participates in all the undertakings – from problem statement up to the ratification of standards and development of end equipment. Intel is now cooperating with companies who have deployed pre-standardized WiMAX broadband wireless networks in over than 125 countries. They offer a wide range of options - from stationary systems of wireless access up to enterprise-scale point-to-point data transmission systems.

Among the operators collaborating with Intel at the promoting of WiMAX solutions are AT&T (USA), Altitude Telecom (France), BT (U.K.), Brazil Telecom (Brazil), ETB (Columbia), Iberbanda (Spain), Millicom (Argentina), Qwest (USA), Sify (India), Speakeasy (USA), Telkom (South Africa), Telmex (Mexico), TowerStream (USA), and the already mentioned "Ukrainian Advanced Technologies" (Ukraine). The release of produce manufactured on the base of Intel PRO/Wireless 5116 has been announced by Airspan, Alvarion, Aperto Networks, Axxcelera Broadband Wireless, Gemtek, Huawei, Proxim Corporation, Redline Communications, Siemens Mobile, SR Telecom, and ZTE.

Remarkably, these days Motorola and Intel announced their joint plans for promoting the IEEE 802.16e-based WiMAX technology for mobile solutions and which is applicable to both stationary and wireless devices fir broadband communications. Apart from promoting the WiMAX standards, the joint plans of these companies include tests of mobile devices, networked and subscriber end equipment made by Motorola for compatibility to Intel's produce.

WiMAX in Russia

Late in October, the first in Russia seminar on using the WiMAX arranged by Intel was held in Nizhny Novgorod. The seminar gathered representatives, telecommunication companies, providers, developers and manufacturers of wireless communications equipment, as well as government institutions in charge of frequency regulations and licensing. During the event, Intel representatives demonstrated a model of operating network built on the base of the Intel Pro/Wireless 5116 chipset.

Alas - not all are as enthusiastic as Intel. As regards the real dates for introduction of a new backbone wireless standard in Russia, many analysts agree that formation of WiMAX networks in Russia will not start earlier than the summer of 2006. Many pledge to the incomplete certification for WiMAX equipment, many complain about the high price of first-generation WiMAX solutions, but in general there is a lack of intention from the side of providers to spend for a technology which is unlikely to pay back soon. In large cities where there are still more than enough facilities for fast-speed Internet access, the Wi-Fi capacity is still enough. As regards deployment of WiMAX networks somewhere in remote areas in Russia, no one is yet planning to do so at the first stage. Of course, there will be isolated instances of WiMAX network deployment, but we won't hear about them in the near future. But while there is little interest from administrative bodies and lack funding all these events will still be unique.

In a word, many agree that WiMAX networks are unlikely to go beyond the boundaries of large Russian cities earlier than 2009. At the same time, in the Net you can find a variety of contrary opinions stating that if introduction of WiMAX networks at the first stage proves successful, their number may go up as a snowball within short terms.

Perhaps I'd rather stop my today's story at the note of uncertainty. Early in 2006, the WiMAX standard is in for another epochal event and we'll hope that by that time the news on Russian market of WiMAX networks will be more optimistic.

WiMAX: wireless highway to the future

By: Vladimir Romanchenko

At first, there was the cable. No, that's wrong. First, there was the word, of course, and then the deed which resulted later in computers and other electronics - from super-clusters to mobiles. Then there rose the need for interaction among all this electronics. This is the way how the cable came into being, that is, first hard-wire interfaces. Then wireless, as technologies progressed. Leaving this long and sometimes heroic past of hard-wire networks outside the note, let's move on to the most interesting part - the current situation and the nearest future wireless prospects.

Separate Wi-Fi access points that could be plugged in to powerful backbone "hard-wire" networks, e.g. fiber-optical, were the first timid moves towards creation of wireless networks. Then there came up a new class of providers who deployed numerous commercial networks, thus in a matter of few years Wi-Fi networks turned into serious infrastructures - corporate and public. By now, many hotels, airports, and railway stations of the world have acquired Wi-Fi networks, and in some countries residential communities are covered this way.

No doubt, introduction of Wi-Fi wireless networks has proved a revolutionary solution to the "last mile" problem. However, the standard's original limitations for data exchange rate and range, number of channels, high cost of the infrastructure have not yet made it possible for Wi-Fi to become a total threat to cellular networks on the one hand, and hard-wire networks, on the other. Even despite the substantial advantages and introduction of new, more up-to-date versions of the standard, the "native limitations" of Wi-Fi will be eliminated only through new backbone standards for data exchange. Sort of WiMAX.

WiMAX Definition

WiMAX stands for Worldwide Interoperability for Microwave Access, and is a technology of broadband wireless communication standardized by the IEEE which complements DSL lines and cable technologies as an alternative solution to the "last mile" problem at great distances. The WiMAX technology can be used to implement broadband "last mile" connections, deployment of wireless access point, arrangement of high-speed communication among company branches and solution of other similar tasks.

Evolution of WiMAX

The preliminary version of WiMAX provided functionality with the equipment which was not subject to standard tests for compatibility to the WiMAX technology. A number of service providers are still using such preliminary hardware solutions to implement WiMAX pilot projects in many parts of the world. Once tests for compatibility of these systems to the WiMAX technology are complete, they will most likely be upgraded programmatically in compliance with the requirements of the final WiMAX standard.

In ideal, the wireless technology WiMAX based on industrial standards is developed to provide inexpensive high-speed communication for residential areas, enterprises, and mobile networks in cities and in rural areas. Note the definition - it contains a "niche" for the interaction of backbone WiMAX with the "local" Wi-Fi.

Outlooks for WiMAX in the nearest future

Today's WiMAX in the version IEEE 802.16-2004 is a standard of wireless communication, which provides broadband communication in the area of over 30 km in range with the bandwidth comparable to that for cable bonds - up to 10 Mbit/s and higher. The WiMAX technology allows operating in any conditions, including in the dense urban coverage, and providing a high quality of communications and data transmission rate.

The equipment of WiMAX networks operates in several frequency channels of 10 MHz width within the range from 2 GHz to 11 GHz. Certainly, the specific distribution of frequency ranges in various countries calls for the need to operate WiMAX in various sectors. Such a wide discrepancy of ranges has been selected to cover the specifics of most countries of the world. For instance, in the North America the WiMAX uses sectors in the 2.5 and 5 GHz ranges, in the Central and South America - 2.5, 3.5, and 5 GHz, in the Middle East , Africa, Western and Eastern Europe - 3.5 and 5 GHz, in the Asian Pacific region - 2.3, 3.5, and 5 GHz.

Essentially, WiMAX is a technology that provides access to Internet at T1 speed with the performance and coverage much higher than in modern Wi-Fi networks. In its turn, local Wi-Fi networks, various types of business and household cable/DSL networks of end users are just the continuation of WiMAX "backbone branches".

Establishing communications within 10 km range and farther, WiMAX points provide coverage of vast areas thus giving providers flexible enough conditions to ensure the very "last mile communication".

On the whole, the base characteristic of 802.16 standard provide a reach as far as 50 km, and coverage with the possible operation outside the direct visibility zone, which in prospect will give a peak data exchange rate up to 70 Mbit/s per sector, with the typical base station having up to coverage sectors.

Today, introduction of WiMAX is subdivided into the three main stages. The current first stage implies introduction and wide distribution of the WiMAX technology of EEE 802.16-2004 standard which came to replace the earlier versions IEEE 802.16a and 802.16d, and which uses external aerials of the "cellular disc" type aimed at consumers in fixed directions.

The second stage implies use of internal aerials, simplified and more flexible use of WiMAX to provide access.

The third stage promises a wide introduction of IEEE 802.16e specifications whose ratification is expected in early 2006, and the emergence of first networks expected in 2007. That means the possibility for operating WiMAX-Certified solutions even as part of portable devices moving across the certain "coverage area" of the network, in the image and likeness of modern cellular and Wi-Fi networks.

Development of such complex standards implies co-existence with other wireless standards, including cellular networks, development of new generations of "smart" aerials, application of new type of modulation like OFDMA, new types of services like QoS, data protection, and many other parameters. In this WiMAX review, we are not giving a detailed account of all the fine points of new standards, but in fact it is a long and painstaking process.

As regards the capabilities of the first-generation WiMAX - IEEE 802.16-2004, in ideal, each base station provides coverage within the range of up to 50 km at data exchange rate up to 35 Mbit/s. In practice, the width and respective performance of the channel is "sliced" for the end user by the service provider. But the way, the architecture of WiMAX networks which in ideal resembles honeycombs (but of a much larger "cell") implies placing antenna-feeder devices on high buildings, structures, and masts. No wonder that interest to the deployment of WiMAX networks was shown primarily by cellular network providers: however strong the competition between WiMAX and 3G/4G networks is, it is much cheaper to install and service several types of equipment on the same mast rather than on several ones. In any case, it is up to the consumer to decide whether to give preference to a specific network.

Today, maximum attention to the introduction of WiMAX networks is paid in the countries of vast territories and great distances from cities, as well as high percentage of rural population. Even for the most developed countries like Sweden it is of advantage to introduce WiMAX as an alternative to hard-wire backbone communications, GSM/EDGE and 3G networks. Needless to say, developing countries like China, India, and Russia will have to start from scratch.

More jobs cut as Alcatel-Lucent suffers through Q3

By Matt Kapko

Alcatel-Lucent lost more than $373 million during the past quarter the company reported as it announced it would be replacing its chief financial officer. Wall Street appeared relatively pleased with the results, which mostly fell in line with the company’s revised outlook. Alcatel-Lucent's stock was up nearly 3% to $9.67 after the news.

As the company cut around 1,000 jobs during the third quarter its revenues fell 7.8% from the year ago period. The recently combined company has cut more than 5,000 jobs since the beginning of the year and plans to achieve its targeted savings of $867 million through the cuts by year’s end.

“As you can see our results this quarter were essentially in line with the update we provided on Sept. 13, and in a few areas a bit better; however they are still not at a level that we are satisfied with,” CEO Pat Russo said in a statement.

Wireless revenues dipped at least 20% from the year-ago period.

“During the first nine months of operations as a single company, we strengthened our position in key strategic markets and technologies such as IP and mobile broadband required to position the company for long-term sustained growth. Having said that, and in spite of the promise of this industry and the long term benefits of the merger, we recognize that market conditions remain difficult, with continued pressure on revenues and margins due to intensified competition and some slowdown of spending in North America,” Russo added.

The company announced plans to further streamline the organization as it aims to cut costs by an additional $578 million by the end of 2009. Alcatel-Lucent said it will accelerate its ongoing job cuts with an additional 4,000 set to be out of a job by 2009.

“These are difficult but necessary decisions, and we will manage these reductions with care. With this plan, the company is targeting gross margins in the high 30’s and operating margins of 10% or better in the post integration phase beginning 2010,” Russo said.

The company also announced that Hubert de Pesquidoux would be replacing CFO Jean-Pascal Beaufret, who is leaving the company to pursue other opportunities.

Alcatel-Lucent shows off WiMAX handoff in Dominican Republic

By Matt Kapko

Alcatel-Lucent and Dominican Republic-based operator Onemax announced that they’ve completed the world’s first mobile handoffs on a commercial WiMAX 802.16e-2005 network in the 3.5 gigahertz spectrum band just one day after the companies officially launched the network.

Onemax executives, customers, local celebrities and government dignitaries were all on hand to view video telephony, high-definition streaming video, mobile broadband Internet access and Voice over Internet Protocl services in Santo Domingo, the nation’s capital. The services, which were supported with an IP Multimedia Subsystem (IMS) core, were delivered over the Onemax network to users traveling in a van.

“This achievement highlights the readiness of our network today, to offer a whole new range of compelling broadband services to residents of the Dominican Republic as well as visitors,” said Raoul Fontanez, Onemax’s CEO. “This collaboration with Alcatel-Lucent’s also is enabling us to give our customers and other distinguished guests a taste of some of the more advanced multimedia services that we will be able to introduce in the future.”

Onemax is the first service provider in the country to offer full nationwide wireless high-speed broadband Internet, multimedia and VoIP services, the company added. Alcatel-Lucent’s WiMAX Rev-e solution provides wireless broadband access in fixed, nomadic and mobile environments, the companies said.

“These achievements show that WiMAX is here today and poised to play an increasingly critical role in the delivery of mobile broadband services worldwide,” said Oliver Picard, president of Alcatel-Lucent’s activities in Europe and the South America.

Infrastructure awards wrap-up: Colubris, Nokia Siemens Networks, BelAir Networks and more

By Kristen Beckman

The following list details this week's infrastructure awards for the cellular, Wi-Fi, and WiMAX industries. The contracts are broken down by transmission technology, country and vendor. The value of the contract is included when available.

Wi-Fi

--France: Colubris Networks said it has been chosen by Alcatel-Lucent and French operator SFR to provide Wi-Fi equipment for a municipal Wi-Fi network in Paris.

Miscellaneous

--China: Nokia Siemens Networks said it won a convergent charging deal with Guangdong Telecom to provide its charge@once convergent online charging solution for prepaid and postpaid online charging for future mobile and data subscribers. Nokia Siemens Networks also announced a deal calling for it to enhance railway communications for the Hefei-Nanjing line with GSM-R technology.

--Europe: Deutsche Telekom awarded a contract to Nokia Siemens Networks for managed services and next-generation network modernization.

--United States: BelAir Networks said it has been selected by RedMoon Inc. to provide its wireless broadband mesh equipment to cover the town of Addison, Texas. Also in the United States, Cellular South awarded a contract to Alcatel-Lucent to upgrade the carrier’s network in Memphis and Jackson, Miss. The deal is valued at up to $55 million.

Designing Cableless Devices with the Bluetooth Specification

There is an overwhelming desire to clear up the clutter of too many wires at work and at home. Bluetooth is the technology that will enable this type of wireless communication. Before this wireless utopia can be achieved, many issues, including interoperability, must be addressed.

By BurkGehring and Stelios Koutroubinas


Bluetooth is an open global standard intended to replace all kinds of cables using short-range radio technology. Originally conceived by Ericsson, IBM, Intel, Nokia, and Toshiba to develop an open specification for short-range wireless connectivity between laptop computers and cellular telephones, the Bluetooth Special Interest Group (SIG) has expanded to over 1,000 members. Since the market for Bluetooth devices is estimated to be as large as $3 billion by 2005, many designers will be incorporating Bluetooth connectivity into their designs. 1

Bluetooth devices will replace RS-232, parallel, Universal Serial Bus (USB), and other types of cables with a single, standard wireless connection. Thus, any Bluetooth-certified device will be able to communicate with any other Bluetooth-certified device. For example, a Bluetooth-certified personal digital assistant (PDA) or cellular phone will work with any personal computer equipped with a Bluetooth-certified card.

The earliest applications are expected to include cable replacement for laptops, PDAs, mobile phones, and digital cameras, to name a few. Bluetooth supports voice as well as data transmission, so headsets used in the office or home could also become wireless.

Because Bluetooth is a global standard that uses a universally-available unlicensed portion of the radio frequency spectrum, Bluetooth-certified devices will interact in the same way in any part of the world.


How does it work?

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Any Bluetooth system has four basic parts: a radio (RF section) that receives and transmits data and voice; a baseband or link control unit that processes the transmitted or received data; link management software that manages the transmission; and supporting application software.


Bluetooth radio. The Bluetooth radio is a short-distance, low-power radio that operates in the unlicensed spectrum of 2.4 GHz, using a nominal antenna power of 0 dBm. At 0 dBm, the range is 10 meters, meaning equipment must be within 10 meters of each other (about 33 feet) to communicate using the Bluetooth standard. Optionally, a range of 100 meters (about 328 feet) may be achieved by using an antenna power of 20 dBm. Data is transmitted at a maximum gross rate of up to 1 Mbps. Communication protocol overhead limits the practical data rate to a little over 721 kbps. Interference or being out of range may increase the bit error rate (BER) and require packets to be re-sent, further decreasing the achievable data rate.

The 2.4-GHz frequency is shared by other types of equipment: microwave ovens; LANs; and industrial, security, and medical applications. As a result, interference with Bluetooth devices seems inevitable. The Bluetooth specification addresses this issue by employing frequency-hopping spread-spectrum techniques. Bluetooth uses seventy-nine hop frequencies spaced 1 MHz apart in the frequency range of 2.402 to 2.480 GHz. The hop rate is 1,600 hops per second (625-�s dwell time, at each frequency). If the transmission encounters interference, it waits for the next frequency hop and re-transmits on a new frequency.


Baseband . In wireless communications, the baseband is the hardware that turns received radio signals into a digital form, which can be processed by the host application. It also converts digital or voice data into a form that can be transmitted using a radio signal.

Each packet contains information about where it is coming from, what frequency it is using, and where it is going. Packets also contain information on how the data was compressed, the order in which the packets were transmitted, and information used to verify the effectiveness of the transmission. When the data is received it is checked for accuracy, extracted from the packet, reassembled, decompressed, and possibly filtered.

The baseband processor handles all the tasks just described. It takes care of converting data from one form to another (such as from voice to digital data), compressing it, putting it into packets, taking it out of packets, assigning identifiers and error correction information, and then reversing the entire process for data that is received. In Bluetooth, the baseband function is called the link controller.


Links. The Bluetooth link is the method of data transmission to be used. The Bluetooth standard supports two link types – synchronous connection-oriented (SCO) links, used primarily for voice communications, and asynchronous connectionless (ACL) links for packet data. Each link type supports sixteen different packet types that are used, depending on the application. Any two devices in a Bluetooth system may use either link type and may change link types during a transmission.


Link management. The link manager software runs on a microprocessor and manages the communication between Bluetooth devices. Each Bluetooth device has its own link manager, which discovers other remote link managers, and communicates with them to handle link setup, negotiate features, authenticate QoS, and to encrypt and adjust data rate on link, dynamically.


Link controller. The link controller is a supervisory function that handles all of the Bluetooth baseband functions and supports the link manager. It sends and receives data, identifies the sending device, performs authentication and ciphering functions, determines what type of frame to use on a slot-by-slot basis, directs how devices will listen for transmissions from other devices, or puts devices into various power-save modes according to Bluetooth-specified procedures. Each packet uses a single 625-�s timeslot, but can be extended to cover up to five slots. Bluetooth supports an asynchronous data channel, three synchronous voice channels at 64 kbps, or simultaneous asynchronous data and synchronous voice channels. The asynchronous channel can support an asymmetric link of 721 kbps in either direction and 57.6 kbps in the return direction, or a 432.6-kbps symmetric link.


Application software. The application software is embedded in the device that operates an application over the Bluetooth protocol stack. This software allows the PDA, mobile phone, or keyboard to do its job. All Bluetooth devices must have compatible sections in their Bluetooth stack, so that all Bluetooth devices will be able to interoperate with each other.

All Bluetooth-certified devices must have the components described above, to be in accordance with the Bluetooth standard. The standard and certification procedures guarantee global interoperability between devices.



Designing Bluetooth applications

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All Bluetooth designs require a transceiver and a baseband controller that meet the Bluetooth specification. An antenna and a microcontroller (MCU) to run the link control, link manager, and host controller interface (HCI) and/or logical link control and adaptation protocol (L2CAP) firmware are also needed. Alternatively, developers can choose to implement protocols up to, and including, HCI on the microcontroller, and to implement a counterpart of HCI (the HCI driver) and L2CAP on a machine that hosts the Bluetooth chip-set (such as a PC or a second microcontroller on the same or attached printed circuit board).

Quite a few choices for the Bluetooth hardware are available. Several vendors plan to offer Bluetooth baseband ICs, transceiver ICs, or both. Others are offering integrated solutions that include the baseband, radio, microcontroller, and memory. The Bluetooth SIG has a target for a fully-integrated Bluetooth solution priced at $5 or less by the year 2001. In this type of solution, developing the firmware and meeting timing constraints will be a major challenge.



Processor selection

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The Bluetooth baseband has rigorous timing requirements, so the chosen processor must be able to deliver sufficient throughput, consume minimal power, and be cost effective. One of the key design issues is whether to use dedicated hardware for the link controller or to implement link control in the chipset's microcontroller. The Bluetooth spec follows little endian convention, so the microcontroller should also support little endian operation. Since the microcontroller should be able to handle multibyte vectors, a 32-bit device is preferable. This is particularly true if security features are to be implemented. The MCU compiler will have to provide dense and highly-optimized object code because program space and/or timing requirements are critical.


Baseband timing constraints

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The granularity of the processing in the baseband layer will need to be one-half of a Bluetooth slot (312.5 �s) because some access procedures produce two packets per slot and because FHSS inquiry response packets may start at a half-slot boundary.

The transceiver is heavily restricted by Tvco and Tpower_up. Although there are procedures that the firmware can execute during Tvco and Tpower_up, it is vital that the firmware has decided what should be done with the next slot in the time duration 321.5 �s minus all the previously-described time periods (Tvco+Tpower_up+ Tuncertainty_window+Taccess_code). Thus, the link control functionality should be implemented as a finite-state machine that runs in interrupt mode, and the execution of the link control code should be synchronized with the slot boundaries.



Hardware/software partitioning

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Due to the rigid timing constraints on the Bluetooth baseband, designers should consider replacing some of the Bluetooth firmware blocks with dedicated hardware. This is particularly true for time-consuming and/or time-critical procedures such as LSFRs (header error correction, forward error correction [FEC], cyclical redundancy check, data whitening, and testing the bit sequence). Each packet type and each packet field requires different bit transformations (such as FEC or data whitening). By implementing these functions in the hardware, the packet type and current field can be traced during receive/transmit to quickly decide which transformations should be enabled or disabled.

Additional baseband functions which can be implemented in the hardware include low-level security functions such as cipher stream generation and authentication SAFER algorithms. Implementing these tasks in the hardware relieves the MCU of having to perform them, thereby speeding up firmware execution. It also reduces the required amount of system SRAM and Flash memory. Using an off-the-shelf RTOS that supports the multithreading and scheduling requirements of the Bluetooth specification is another option. The RTOS should be able to implement context switching and service interrupts quickly, in order to meet the Tfirmware constraints, and should also have an acceptable memory footprint – especially for a fully-integrated Bluetooth solution.



Bluetooth Radio

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Several members of the Bluetooth SIG are developing single-chip Bluetooth radios. The Bluetooth standard requires a receive sensitivity of -70 dBm, so any Bluetooth certified radio will have been tested to meet this standard. However, increasing the receive sensitivity gives the designer the freedom to implement designs that have a longer range than the 10 meters in the Bluetooth specification. At -80 dBm, the Bluetooth application could have a range of 100 meters, an advantage that could be extremely useful in some applications. Since the BER is largely dependent on the maximum distance between the two Bluetooth devices, a transceiver IC with a higher rating will also have a smaller BER, which allows the Bluetooth device to achieve a higher data rate.

GSM phones have a maximum output power in the range of 1 to 3W, and receive and transmit frequencies ranging from 890 to 1,990 MHz, while Bluetooth transceivers are designed to work with signals as low as 10pW. Noise from the phone's transmitter may interfere with the Bluetooth signal. A trap can be placed at the output of the transmitter to attenuate any energy radiated in the 2.4 GHz band.

In most RF systems the transmit data modulates the VCO by switching the charge pump in tri-state while the phase-locked loop (PLL) is in open-loop mode. This causes frequency drift that can result in transmission errors. Frequency drift can be controlled by using I&Q modulation in which I&Q signals are transmitted by the baseband to the RF section during the mixer stage to stabilize the frequency. This requires additional firmware in the baseband, as well as off-chip passive filters. Another approach is to use a modulation compensation circuit (MCC) that keeps the VCO frequency stable while the PLL is in closed-loop mode. This latter approach to demodulation eliminates the need for any external filters. It also allows the collocation of several time slots, increasing the effective data rate. Since closed-loop modulation is insensitive to tolerances and noise influences, it results in better performance.

All superheterodyne radios tend to receive two frequencies – the signal frequency and the image frequency. An unwanted signal at the image frequency must be suppressed to avoid interference with the desired signal. One means of doing this is to use an off-chip passive filter. The external filter will increase system size and add cost, which are drawbacks in portable applications. Another approach is to include the image rejection as part of the mixer on the transceiver. The image rejection mixer converts the frequency down to 111 MHz, a frequency that conserves power and for which many low-cost filters are available.



Power consumption

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Virtually all Bluetooth applications will be battery operated, making power consumption a significant consideration. Implementing some of the baseband functions in hardware allows the MCU clock to be slowed, reducing power drain. Gating the clock to the MCU and the other hardware blocks also helps to minimize power consumption. Processing power varies with time, so it is preferable to drive the MCU with a relatively high-speed clock and to gate the MCU clock when the Bluetooth subsystem is in sleep mode. Using the image rejection mixer to convert the frequency down to 111 MHz, as previously described, also conserves power.

Firmware considerations – HCI

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The HCI protocol structure is described quite clearly in the Bluetooth specification. However, from an implementation point of view, the boundaries between HCI, link manager (LM), and link controller (LC) are not clear from the beginning. So, these layers should be designed carefully and, if possible, developed in parallel in order to integrate the system data structures as much as possible and to avoid data and code redundancy.

The HCI packet structures (Command, Event, ACL, and SCO packets) must be wrapped with additional information relating to the transport layer above HCI that runs on top of the physical link between the Bluetooth device and its host. The dataflow infrastructure must be carefully developed because individual HCI commands do not require the same amount of processing, nor do they remain in the system memory for the same duration. For example, processing the command Read_Local_Version_Information is straightforward when compared to processing the command Create_Connection.


Firmware considerations – L2CAP

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L2CAP is used for protocol multiplexing above the basic Bluetooth layers, for packet segmentation and reassembly, and to convey QoS information. The system designer must first decide whether to embed L2CAP with the rest of the layers or have it running as part of the host OS. Making this decision depends on the usage model and the device that will contain the Bluetooth design. A mobile phone will have to maintain L2CAP in an embedded nonvolatile memory, while a laptop computer will not.

If L2CAP is to be embedded, the designer must take into account the amount of information the Bluetooth subsystem can hold in its receive buffers on the host side before it can fragment them into smaller chunks according to Bluetooth packet sizes. The maximum packet size that L2CAP accepts from a protocol running on top of it is 64 kbytes.

Although the Bluetooth standard specifies which transport layers a Bluetooth device can use to communicate with the host to exchange HCI packets over various physical links (UART, USB), it does not specify any of them for an embedded L2CAP over the same links. Designers will have to consider how this interface is to be realized. If L2CAP is built on the host side, there is always a problem of integrating this layer into the host's OS in a way that ensures protocol multiplexing can take place above it with minimal alterations to the host's driver stack. A host-side L2CAP also poses the problem of interfacing the lower part of the L2CAP with a host-side HCI driver or with another proprietary driver. In the first case, the stack may run slower. In the second case, more programming effort will be needed to achieve interoperability requirements.

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Stelios Koutroubinas is managing director, vice president, and CEO of the board of directors of Atmel Hellas S.A. He holds an engineering degree and a PhD in electrical engineering from the University of Patras, Patras, Greece. He can be reached at steliosk@atmel.gr .

Burkhard Gehring is the technical project leader for Temic Semiconductor's Bluetooth radio IC group. He received the Diplom Ingenieur degree from the Technical University of Dresden, Germany. He can be reached at burkhard.gehring@temic_semi.com

802.11 vs. 3G

Once upon a time, you could hardly open a business magazine without finding a feature that praised third generation (AKA 3G) (define) wireless telephony as the answer to mobile Internet needs. That was venture capital then. This is fiscally strapped now.

In theory, 3G wireless networks are capable of throughput up to 384Kbps, which still puts them at the bottom end of 802.11b's range. In practice, though, 3G isn't available in the United States at all except in experimental deployments.

Instead, we have telecomms using the "3G" name for what's actually, at best, 2.5G. This is a middle step between what we currently have, 2G, basic digital service, and the science fiction speeds of 3G. With 2.5G networks, you can transfer data at rates of up to 114Kbps generally using General Packet Radio Service (GPRS) (define).

So how good is GPRS, really? David Ferris, CEO and analyst for Ferris Research, has "been testing out GPRS connections with mobile phones in major metropolitan areas in the UK and US. These are now being brought on-stream by a wide variety of mobile carriers. In a nutshell, GPRS provides an always-on connection to the Internet. To be precise, GPRS enables per-handset data rates of 9.05-107.2 Kbit/sec depending upon the coding scheme employed and time slots (from 1-8) allocated to a data packet. In practice, we're finding that transfer speeds of 400 to 1000 bytes/sec are the norm."

Translated, what this means is that 2.5G is is in no way competition for 802.11 for moving data. As Ferris explains, performance like this "means that communications need to be kept short, and that, in turn, means most of them will be text-based. E-mails with attachments will usually take much too long to transfer."

Still, he thinks, that "applications like instant messaging, or distributing appointment information, can be run successfully." However, instant messaging or Web browsing on 2.5G or 3G phones isn't what 802.11-enabled laptops users think of as IM or the Web.

On digital phones you must use Short Messaging Service (SMS) (define) or Multimedia Messaging Service (MMS) (define). Without a special gateway between the SMS/MMS servers and consumer IM clients like AOL Instant Messenger (AIM), or business-class IM clients such as Lotus Sametime or NetLert, you can't send messages from IM to someone using MMS or SMS on a digital phone.

On the Web side, for a Web page to be viewed effectively on a digital phone, the signal must be sent in Wireless Application Protocol (WAP) (define) and the page should be written, not in the usual HyperText Makrup Language (HTML) (define) used for most Web pages , but in Wireless Markup Language (WML) (define). In short, viewing Web pages with on 2.5G and 3G is inherently more problematic.

3G is also much more troublesome for telecom carriers to install. To deploy it you must overhaul your wireless infrastructure and replace it. Of course, you must do the same thing with 802.11 hotspots, but while hotspots have far less range, a business class hotspot with advanced antennas also can be deployed for about $1500, while all but the smallest (pico range) 3G base stations start around six figures and move up from there. Anyone can set up a hotspot; only a telephone carrier or corporation can afford 3G base station.

Expert Opinion
What do the analysts think? It depends. Everyone acknowledges that there was a 22% decline in wireless and mobile network infrastructure spending in 2002. Research house IDC, for one, in its Worldwide Wireless and Mobile Network Infrastructure Forecast and Analysis, 2002-2007 study, says that the demand for 2.5 and 3G remains strong. Indeed, IDC expects annual spending on 2.5 and 3G network infrastructure to grow from $38.3 billion in 2002 to nearly $49 billion in 2007. Wireless phone infrastructure providers like Ericsson, Nokia, and Nortel no doubt hope that IDC is right.

"The essential rationale for deployment of 3G networks -- gaining spectrum efficiencies, easing network capacity constraints, lowering operating costs, and expanding revenue opportunities through provisioning of data services -- remains intact," says Dr. Shiv K. Bakhshi, research manager for the IDC's Wireless and Mobile Network Infrastructure program. He believes that the rising popularity of MMS and picture messaging will "legitimize the culture of data consumption in a mobile environment and spur deployment of network infrastructure." But, he notes, it's not just 3G driving these developments; "public WLANs and hotspots" will also help in this development.

"The WLAN industry will continue to experience stellar growth as deployments in several key markets take place," predicts Allied Business Intelligence (ABI) analyst John W. Chang, senior analyst, and some of that growth will come at 3G's expense.

ABI reports in its Worldwide Deployments, Drivers, Players and Forecasts for 802.11x, that "Some of the leading wireless carriers worldwide, including T-Mobile, AT&T, and Verizon, have made announcements of deploying WLAN services as their 3G plans are delayed. WLAN is easier to install and costs far less than setting up a 3G network. In addition, 3G's data rate of 144 kbps, a portable data rate of 384 kbps, and an in-building fixed rate of 2 Mbps are slow, compared to that of WLAN. As WLAN moves toward 54 Mbps, it is apparent that 3G cannot compete with the data rate of WLAN. Though 3G will be deployed worldwide due to its voice capacity benefits, telecom carriers are seeing WLAN hotspots as the immediate revenue generator for data services."

This view is not just that of an analyst looking at plans. On January 29, British Telecomm (BT) announced that it would be deploying 802.11b--and 802.11a soon--hotspots with three business partners. BT plans to have 4,000 hotspots in place by the summer of 2005.

According to David Hughes, BT director of mobility, its BT Openzone hotspot customers will pay 10% of the price to download 1MB of data compared to a 3G user at four times the speed. In short, he declares, "At the moment, it looks like Wi-Fi is one-tenth of the price of 3G, and four times as fast." Even with 3G's much better range, which would you rather have?

Some analysts, like ABI's director of automotive electronics Frank Viquez, think that, "802.11 promises to have the most potential, given its minimum raw bandwidth of 10 Mbps and dramatic growth outside the vehicle industry," even when a wireless data user is traveling at speed.

Can the two technologies get along? Some experts think they can, but given the stalled economy and 802.11's lower price, deployment costs alone may cause 3G to flounder. Who knows? Instead of 3G laptops in 2007, perhaps we'll have 802.11 mobile phones.

3G Wireless Technology Quick Guide

Practical 3G wireless technology information extracted from many books.

A comprehensive and clear architecture map of mobile wireless network of both UMTS and CDMA2000.

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UMTS and CDMA2000 network architectures

Detailed CDMA2000 and UMTS communication interfaces between systems and protocol stacks.

Graphic illustration of the evolution path and roadmaps of mobile wireless standards for both GSM/GPRS/WCDMA and cdmaOne/CDMA2000 networks.

Radio Access Network (RAN) features and characters for both UMTS and CDMA2000.

Clear channel mapping charts for both WCDMA and CDMA2000 systems.

Up-to-date illustration of the 3GPP IMS and 3GPP2 MMD.

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Designed for mobile wireless technology engineers and network admins, wireless communication technology educators and students, this 3G mobile wireless technology quick guide covers all major 3G wireless technologies: UMTS and CDMA2000 architectures, Wireless Radio Access Network(RAN) technologies, WCDMA and CDMA2000 channels, CDMA and UMTS interfaces and protocols, 3GPP IP Multimedia Subsystem (IMS) and 3GPP2 Multimedia Domain (MMD) and the evolution path and roadmap for both the GSM/GPRS/UMTS and CDMA/CDMA2000 neworks.

Wireless hardware, software and service vendors may purchase it as a marketing or sales tool in trade shows, seminars and web/email leads generation programs. Networking and telecom IT training organizations can use it as a supplementary educational tool or a motivational gift for students and trainees. We have special product customization

Wireless Digital Camera Guide

by Photo-John

What's a Wireless Digital Camera? What does WiFi have to do with digital cameras, you ask? Wireless digital cameras allow you to connect to a wireless network without using any cables. This makes it possible to download photos, save photos directly to a computer while you shoot, or print wirelessly. You can even connect to a cellular network and share photos, just as you would with a camera phone. How Does a WiFi Camera Work? WiFi cameras use wireless computer networking technology (802.11b and g) to connect to a wireless network. If you have a wireless network at home or work, you can connect to it with a wireless-enabled digital camera and download your photos to a computer without any cables. This means easier image downloads, printing, and photo sharing. Imagine not needing a card reader or USB cable to download or print photos anymore! The Cameras Kodak was the first to announce a wireless-enabled digital camera - the EasyShare-One, at the 2005 CES tradeshow. Canon, Kodak, and Nikon all started shipping WiFi digital cameras last year (2005). Currently, (April 2006), there are three wireless compact cameras available and Nikon will be delivering two new models, shortly. The cameras range from the 4-megapixel Kodak EasyShare-One to the 8.1-megapixel Nikon Coolpix P3 (available in May). All of the wireless cameras are fairly standard point-and-shoots as far as camera features go. Nikon's two P-Series wireless digital cameras offer the most exposure control with an aperture priority mode as well as standard programmed auto and scene modes. The pocket-sized Nikon Coolpix S6 sets itself apart from the other WiFi cameras with Nikon's VR Vibration Reduction, which helps reduce blurry photos caused by camera shake. The Kodak EasyShare-One is the most unique camera of the bunch. It's more like a PDA than a camera. With its wireless card and articulated 3-inch touch screen LCD and stylus, it's very different than any other camera currently available. Like all Kodak EasyShare cameras, it was designed with photo sharing and the Kodak EasyShare Gallery in mind. With the wireless card, the "share" button allows you to e-mail photos or wirelessly access the Kodak EasyShare Gallery to view and upload photos. As seen at PMA 2006 - The Nikon Coolpix P3 - an 8-megapixel wireless digital camera, equipped with Nikon's VR optical Vibration Reduction. With point-and-shoot simplicity and a compact design, the Canon PowerShot SD430 follows in the proven Canon Digital ELPH tradition. It distinguishes itself from the other cameras with one very cool wireless feature. You can set up the SD430 remotely, and take pictures wirelessly, using your computer to control the camera. Canon's PowerShot SD430 Web Page shows the camera being used for wildlife photos and baby monitoring - two logical applications. Conclusion Wireless technology is another way to transfer images from your digital camera to a computer, printer, or even the Internet. It's an extension of what thousands of people are already doing with their camera phones. The difference being, with a wireless camera, the emphasis is on photo quality and camera features - not the phone. So you get some of the cool wireless functionality of a camera phone, but in a "real" camera the offers more control and better photo quality. Wireless connectivity is the future. In a couple of years, most cables will probably be unnecessary. Currently, wireless devices and wireless networks are notoriously finicky and the technology is confusing to the average person (it confuses me). So it's probably a bit early for some people to run out and buy a wireless digital camera. That said, when it works, wireless connectivity is very cool and super convenient. Just remember, if you do buy a wireless camera, you can consider yourself an "early adopter" with all the glory and hassle that entails. - end -