Electronic Design

Communications: Wireless Networks

Wireless LANs, PANs, And More Continue To Roll

Wireless is booming, and we're not just talking cell phones. Wireless local-area networks (WLANs), personal-area networks (PANs), and special wireless applications are seeing excellent growth, riding against the grain of the past two down years.

Evolving wireless technology has opened up other heretofore wired-only applications. The potential use of ultra-wideband (UWB) in transmitting video in home-entertainment networks is one example. Radio-frequency identification (RFID) is another. Even something as old and typically boring like broadcast radio is experiencing some major new developments.

The shining star of wireless right now involves Wi-Fi WLAN products using the IEEE 802.11b 11-Mbit/s technology. Not only has it helped expand enterprise networks and improve mobility, it's also fostered an astonishing array of new and unexpected applications. Some examples are wireless hot spots or access points, wireless home networks, and broadband Internet connections where cable and digital subscriber line (DSL) don't exist.

Also available are 802.11a modems that achieve data rates up to 54 Mbits/s. While their range is more limited than 802.11b modems, the higher speed solves some problems.

The biggest development, the 802.11g standard, essentially expands the 802.11b capabilities in the 2.4-GHz band. By using OFDM, it offers speeds to 54 Mbits/s and full backward-compatibility and interoperability with 802.11b systems. That may ultimately kill the 802.11a products.

In the PAN space, Bluetooth is generally a big success. Applications include cable replacements in wireless cell-phone headsets, PDA links to PCs, laptop links to cell phones, and wireless RS-232 and RS-485 interfaces. The high volume price has dropped under $5, making Bluetooth a candidate for many other applications.

Another wireless PAN development is ZigBee. This wireless standard is simpler and cheaper than Bluetooth. It's expected to find applications in industrial monitoring and control, sensor networks, home monitoring and control, security systems, and toys.

UWB is yet another recent wireless advance. The FCC recently approved UWB operations in the 3.1- to 10.6-GHz band. Several companies are developing high-speed (100 Mbits/s+) transceivers to be used in video home-entertainment networks.

A real sleeper of a wireless technology is RFID. Previously only used in automated toll collection and in purchasing systems like Mobil's SpeedPass, RFID is rapidly expanding into bar-code territory to track shipments, manage assets, and minimize inventory control problems. Prices are dropping as products are developed for new applications.

In wireless broadcasting, the XM Radio and Sirius low-earth-orbit satellite subscription radio services operating in the 2.3-GHz band beam over 100 channels of commercial-free, digital-audio-quality sound to cars coast to coast. Expectations are high as more cars are equipped with these radios.

Meanwhile, startup iBiquity is looking to revolutionize standard AM and FM radio by squeezing digital audio into the same bandwidth as the current analog signals, providing a real fidelity upgrade. This technology should start to appear in real products in the near future.

Some additional developments on the horizon include wireless broadband Internet access, UWB radars in your car for automatic braking, and more software-defined radios.

>WI-FI 802.11B WIRELESS LOCAL-AREA NETWORKS (WLANs) will continue to grow. They're popular in larger companies, but it now seems like everyone is getting in on the hot wireless LAN action. The networks are also making inroads in hospitals, colleges, and universities, as well as factories and warehouses.

>802.11G WLANS WILL BE A HUGE SUCCESS, far overshadowing 802.11a systems. This new standard is so popular that semiconductor companies are beginning to sell their chips, and equipment vendors are rushing out WLAN products before the final draft is ratified. While ratification is expected by mid-2003, it's still a big risk that vendors seem willing to take to get a head start in this competitive field. The 802.11g standard is backward-compatible with 802.11b systems, but it also permits data rates up to 54 bits/s. Combined b/g, a/b, and a/g chip sets will give users the radio modem that best fits their unique needs.

>THE WIRELESS LAN SECURITY PROBLEM will eventually be resolved. One of the reasons why some organizations have not bought WLANs is the technology's poor security. The inherent 802.11b Wired-Equivalent Privacy (WEP) is not strong enough for many. Newer, more secure systems have yet to be released as well. The ultimate solution is the IEEE 802.11i standard. This fixes the problem with the National Institute of Standards and Technology's Advanced Encryption Standard (AES), which will not be ratified until sometime late next year. Interim fixes will use Wi-Fi's Protected Access (WPA), an improved version of WEP.

>THE NUMBER OF WI-FI HOT SPOTS will explode. These 802.11b access ports have become very popular with those who use WLAN-enabled laptops. Several thousand already exist. But you can expect to see many more as the major wireless carriers implement them in strategic locations around town. Mesh networks using the 802.11b standard are also growing in outlying communities that lack broadband Internet access. Mesh networks allow any 802.11b/a adapter node to link to any other nodes in a peer-to-peer connection to reach a WLAN access point.

>HOME NETWORKS WILL EXPERIENCE AN UPTURN primarily because of proven low-cost wireless technology. The small, nascent home-networking market is already dominated by Wi-Fi, but it will continue to grow as the economy improves. Other wireless technologies will find their way into the home in the form of home control networks with ZigBee.

>BLUETOOTH WILL CONTINUE TO SURPRISE everyone with its increased usage. Bluetooth has already proven the naysayers wrong. It's now showing up in cell phones, PDAs, laptops, and some computer peripherals. With falling unit prices, expect to see even more creative future applications. A standard upgrade later in the year to higher speeds, a voice profile, and adaptive frequency hopping will further extend Bluetooth's useful life.

>THE NEW ZIGBEE PAN STANDARD will find a niche in the already crowded wireless mix. With a maximum 250-kbit/s data rate, it won't compete with 802.11b or Bluetooth. But it will be a less expensive wireless option for home control, toys, and especially industrial monitoring and control networks. It's expected to be ratified as one of the IEEE 802.15 PAN standards in 2003.

>UWB WILL WIN THE BATTLE. A controversial wireless technology that transmits data by spreading the signal over a very wide bandwidth, UWB will be criticized, scrutinized, and brutalized as opponents warn of the dire consequences of UWB interference with cell phones, navigation, and government/military radios. Yet the FCC will be proven right, as UWB products will not produce the expected interference and will ultimately find their way into niches like entertainment video transmissions in home networks and short-range automobile radars.

>RADIO-FREQUENCY IDENTIFICATION (RFID) will proliferate beyond everyone's expectations. Around for years in wireless toll collection and cashless gas-pump transactions, RFID will be more widely used in tracking shipments, inventory, and major assets. It will even replace bar code on larger, costlier products. As new products are developed and costs decrease, new applications will be found, some in security systems.

>DIGITAL BROADCAST RADIO WILL BE A BIG SUCCESS. Digital satellite radio from Sirius and XM Radio came online this past year. This market segment is expected to grow as the radios become more widely available—especially as it's offered as standard equipment in some high-end cars—and as public awareness of the technology increases. Then again, maybe it won't because of a competing digital radio technology from iBiquity. This startup company's development permits CD-quality digital broadcasts in the existing AM and FM radio bands. Whichever technology wins, consumers will get much higher-quality radio in the near future.

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