Exploring the Wireless Lanscape

Exploring the Wireless Lanscape

INDUSTRY TRENDS The technologies are not well estab- lished yet, though, and they still face such Exploring challenges as high costs. Meanwhile, the market has not determined whether one or all of the technologies will succeed. the Wireless WIRELESS LAN TECHNOLOGIES Several companies developed wireless LAN technology about a decade ago. For example, said John Barr, Motorola’s LANscape director of systems architecture and tech- nology for PANs, Motorola developed Altair, one of the first commercial wire- Linda Dailey Paulson less LAN systems. Early wireless LANs were expensive, their data rates were low, they were raditionally, the word “net- prone to signal interference, and most of working” has evoked images of them were based on proprietary RF and yards of spaghetti-like wiring in infrared technologies. T walls, on floors, and hanging from the backs of computers IEEE 802.11b and peripherals. The recently adopted IEEE 802.11b is However, several trends in the com- the newest IEEE 802.11 wireless LAN puter industry are rapidly driving the standard. IEEE developed the 802.11 development and adoption of newer standards to provide an Ethernet-like wireless networking technologies, which wireless networking technology. link devices to each other and to corpo- The European Telecommunications rate LANs, primarily via radio-frequency Standards Institute (ETSI) is looking into (RF) technology. adopting IEEE 802.11 standards, which These trends include the increase in And another industry consortium has would enhance the technology’s interna- home networking; the rapidly growing developed Bluetooth, which many tional interoperability. use of networkable portable devices— experts consider to be wireless PAN (per- The technology. The technology permits such as smart phones, personal digital sonal area network) technology. (See the transmission speeds of up to 11 Mbits per assistants, and laptops—by a mobile sidebar “Bluetooth: The Wireless PAN.”) second, which makes it considerably work force; and the desire by companies Major vendors are beginning to faster than the original IEEE 802.11, to operate networks in historic, leased, develop products using these standards, which sends data at up to 2 Mbps, and a or temporary buildings in which wiring and a number of vendors are working bit faster even than standard Ethernet. is impractical, prohibited, or expensive. with more than one of the technologies. IEEE 802.11b permits devices to estab- Moreover, there is a demand for wire- And now, faster and otherwise lish either peer-to-peer networks or net- less networking by industries, such as improved versions of wireless LAN stan- works based on fixed access points with medicine, in which employees must com- dards are being prepared for release. which mobile nodes can communicate. municate with central networks but are “We’ve been touting wireless LANs IEEE 802.11 operates in the unlicensed too mobile to use wired devices. for six or seven years, and they just have 2.4-GHz so-called industrial, scientific, Meanwhile, improved radio and net- not taken off,” said Eric Thompson, and medical frequency band, which has working technologies have increased the senior analyst with the Gartner Group, become popular for worldwide wireless performance, reliability, and desirability a market research firm. communications because it is globally of wireless networking. However, said Peter Hortensius, direc- available. To maximize the usefulness of wireless tor of technology development for IBM’s On the physical layer, the original LANs, vendors want technology based personal system group, the IEEE 802.11 IEEE 802.11 uses either FHSS (fre- on open standards rather than on pro- standard, backed by established compa- quency-hopping spread spectrum) or prietary technologies, which have been nies, has begun to move wireless LANs DSSS (direct-sequence spread spectrum) used during the past 10 years. into the mainstream. Bluetooth and technologies. With this in mind, the IEEE and two HomeRF are following in a similar path, With both technologies, transmissions industry consortia have developed three he said. HiperLAN appears aimed prin- regularly shift frequencies, which reduces major wireless LAN standards: IEEE cipally at the high-end corporate market, interference and efficiently uses the avail- 802.11, HiperLAN, and HomeRF. primarily in Europe. able bandwidth. However, DSSS sends 12 Computer Bluetooth: The Wireless PAN Bluetooth has been one of the hottest Anders Edlund, Ericsson Mobile Edlund said Bluetooth functions over stories in computer technology, even Communication’s marketing director distances of 10 meters or 100 meters, though vendors have only just begun for Bluetooth, said “We don’t consider depending on the power of the radio releasing products. Bluetooth to be a wireless LAN. It is transceiver being used. The technology Ericsson developed the wireless net- more like a personal network.” permits net throughputs of up to 721 working technology in 1994 to replace Bluetooth personal area networks Kbps upstream and 56 Kbps downstream. the cables used to link computers and (PANs) link enabled devices—such as Bluetooth works with a wireless sys- telephones. The technology has garnered PCs, laptops, smart phones, and personal tem packed onto a chip that can be inte- strong industry support, with about digital assistants—into mininetworks via grated into computers, phones, and 2,000 companies, universities, and other radio signals operating in the 2.4-GHz other devices. organizations joining the Bluetooth spectrum. Bluetooth can also link Ericsson has released a wireless cellu- Special Interest Group (http://www. mininetworks to form a piconetwork. lar headset and two types of cellular bluetooth.com). And many vendors— However, the technology is primarily phones, all equipped with Bluetooth. including Intel, Lucent Technologies, and designed to replace wiring between Meanwhile, other vendors plan to Microsoft—have invested in the tech- devices that are close together, rather implement Bluetooth in their upcoming nology. than create data or voice networks. cellular phone releases. transmissions over a wider channel (11 longer distances. However, wider chan- addition, DSSS uses more power and is MHz) than FHSS (1 MHz) and thus nels also mean that DSSS offers fewer more expensive to build. offers greater transmission speeds over potential channels and less scalability. In IEEE 802.11b uses complementary October 2000 13 Industry Trends Potential commercial applications of Key the high-speed technology include med- HiperLAN identifier Key HiperLAN ical imaging, video training, or remote key set identifier key set surveillance. Key Initialization Key However, HiperLAN has not hit the vector Initialization marketplace yet, as vendors have focused XOR XOR vector more on IEEE 802.11 thus far. Seed Seed “HiperLAN is fancy and it’s new,” Random Random said Barry Davis, strategic marketing Encrypted sequence XOR XOR sequence manager for wireless LAN operations at data generator generator Intel, “but products have never shipped.” Although HiperLAN has been seen as Data Encrypted Data Transmitter transmission Receiver primarily a technology for the European market, it can be used in other areas. For example, the US Federal Communica- Figure 1. In HiperLAN1’s implementation of wired equivalent privacy (WEP) cryptography, a ran- tions Commission (FCC) has allocated dom bit sequence called the initialization vector runs an XOR operation on the encryption key. spectrum for its use. The resulting value helps produce a stream cipher, which is used to encrypt the data. Packets— which include the key identifier, initialization vector, and data—are then sent to the recipient’s HomeRF system, where decryption takes place. HomeRF is based on the shared wire- less access protocol (SWAP), which the code-keying DSSS, which permits faster HiperLAN HomeRF Working Group (http://www. transmission speeds than the original ETSI developed the HiperLAN (high homerf.org) adopted in late 1998. DSSS used in IEEE 802.11. performance radio LAN) standard. The technology, including a faster For security, IEEE 802.11b supports The HiperLAN Alliance (http://www. Wideband HomeRF currently under authentication and encryption, including hiperlan.com) designed the initial version development, is designed for use primar- 128-bit wired equivalent privacy (WEP) of the technology, HiperLAN1; the ily in homes and small offices. cryptography. HiperLAN2 Global Forum (http://www. The technology. SWAP lets up to 127 The market. Apple Computer was the hiperlan2.com) is working on a faster PCs, peripherals, cordless telephones, first company to market IEEE 802.11b version. and other devices with a network stack systems, via its AirPort technology. Air- HiperLAN1 offers up to 23.5 Mbps share and communicate data. SWAP also Port is implemented via add-on cards throughput, the highest performance of permits up to six voice connections. and, in some cases, base stations that let today’s wireless LAN technologies. A HomeRF system can operate either up to 10 devices form networks. Other The technology. The keys to Hiper- as an ad hoc network of devices, which companies, including Cisco Systems and LAN’s high data rate include its efficient support only data communications, or as 3Com, also offer IEEE 802.11b prod- power amplifier and its use of the 5-GHz a managed network under the control of ucts, such as network cards and chips. frequency band. Within the 5-GHz a central connection point. For trans- Gartner’s Thompson predicts

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