Wireless LAN

Too Many Cooks Could Spoil the Soup

05. November 2001
Von Stan Schatt
Der Markt für Wireless Lans ist in Bewegung. Anfang des nächsten Jahres wird die Vielfalt der Protokolle deutlich erweitert. Dabei differieren die Prioritäten der Anbieter: hier höhere Bandbreite, da Quality of Service. Stan Schatt, Analyst der Giga Group, betrachtet die Optionen.

Giga Position The IEEE 802.11b 11Mbps technology currently dominates the wireless local area network (LAN) market. However, customers are bound to get confused over several other options either currently offered or likely to be available early next year, including 22Mbps 802.11g products, 54Mbps 802.11a and HiperLAN/2 products, and low-cost 10Mbps HomeRF products. It is even possible that very inexpensive 1Mbps Bluetooth products will form some networks. As if that's not confusing enough, vendors continue to sell low-cost 2Mbps 802.11 products. These seismic changes taking place in the wireless LAN industry, coupled with some security issues, are likely to cause many potential customers to delay product purchases in the fourth quarter of 2001 unless vendors quickly provide an enhanced security standard and clearly segment the role soon-to-be released products will play and what they will cost. Giga clients should consider delaying fourth-quarter 2001 wireless LAN purchases until the first quarter of 2002 because prices are likely to be lower, and security is likely to be improved. Proof/Notes The Current State of Wireless LANs The Wireless Ethernet Compatibility Alliance (WECA) has done an excellent job promoting the benefits of the IEEE 802.11b standard as well as the benefits of the WIFI certification for interoperability. Today, 802.11b wireless products dominate the market but have not yet achieved the momentum to "cross the chasm" and become commonplace in most corporate network environments. Wireless LANs now serve as supplements to rather than replacements for wired LANs in most environments. The exceptions to this rule are environments such as warehouses, nurses stations, mobile auditing or training networks and isolated reception areas where cabling is difficult. Also, some remote offices or temporary offices where data traffic is relatively low are good candidates for wireless LANs. There are three major reasons why sales of wireless LANs have not grown to match the rosy forecasts of some industry analysts: cost, performance and security. Cost While wireless LAN vendors would like customers to include the cost of cabling when comparing the total cost of a wired LAN with a wireless LAN, the truth is that most corporate IT environments already have CAT 5 cabling installed and probably have already depreciated its cost. Without the cost of cabling included, a wired LAN is at least twice as inexpensive to deploy as its wireless counterpart. While 100Mbps Ethernet technology has become a commodity item costing around $75 per port, IEEE 802.11b wireless LANs only provide a theoretical speed of 11Mbps, which shrinks to less than 6Mbps of throughput because of overhead and because the wireless standard is a shared rather than a switched architecture. In other words, the more users, the less available bandwidth and the slower the network performance. So, customers now pay a premium over the cost of a wired LAN for performance that is approximately 10 times slower. SecuritySecurity Security represents yet another major obstacle to wireless LANs achieving parity with their wired counterparts. While WECA members first argued that the Wireless Equivalent Protocol (WEP) security offered the equivalent level of security of a wired LAN, members have since admitted that security is far less robust for a number of reasons. First, wireless LANs broadcast in all directions. One reporter for an industry publication booted up a laptop with a wireless card in his car parked near a building housing a wireless LAN and was able to access that network. In addition, some wireless access points are configured by default to accept any user as a legitimate network user. Finally, only a 40-bit encryption algorithm is part of the 802.11b specification. Users must opt for a proprietary solution if they want 128-bit encryption. Yet another related security concern is the potential interference threat to 802.11b networks posed by Bluetooth devices. Some tests have confirmed that a Bluetooth device placed next to a wireless node that is some distance from an access point can disrupt network operations. An IEEE 802.15 committee is currently trying to develop a solution to this problem. Performance The IEEE 802.11b specification covers wireless networks broadcasting in the 2.4GHz range. Higher speed wireless LAN development is taking two completely different directions. One group of vendors led by Texas Instruments is supporting a 22Mbps extension of 802.11b that would remain in the 2.4GHz range. The advantage of such a specification is that this technology would be downwardly interoperable with existing 802.11b networks. Products based on it are expected to be a bit less expensive than the 5GHz range IEEE 802.11a products being developed (see below). And while 5GHz products won't work at all with existing 802.11b equipment, 802.11g products will. IEEE 802.11b cards should work at their current speeds with new 802.11g access points, while new 802.11g cards will communicate at 11Mbps with old 802.11b access points. It is possible [.6p] that such products will appear by the end of the first quarter of 2002. The most exciting news for Giga clients planning wireless LANs is the development of the IEEE 802.11a specification for 54Mbps wireless LANs broadcasting in the 5GHz frequency range. Products are expected to ship by the first quarter of 2002 [.7p]. These products will not be interoperable with IEEE 802.11b LANs but will offer enough throughput (probably around 24Mbps) to handle data-intensive applications, such as enterprise resource planning (ERPERP) programs and multimedia. One serious issue that wireless vendors will have to address is how to price the new high-speed products and how much to drop the prices of the older 802.11b products so that customers will find both sets of products attractive and one group will not cannibalize the sales of the other group. Should both IEEE 802.11g and 802.11a products ship around the same time [.6p], customers might very well become confused and decide to wait rather than purchase either technology. This is what happened two years ago when vendors offered frequency hopping and direct sequence products that were both supported by the IEEE 802.11 specification at 2.4GHz. Vendors threw enough mud at each other and published enough vitriolic attacks against the competing technology to cause potential customers to become so confused that they failed to make a buying decision. The result was a wireless LAN market that failed to match many industry forecasts. The Number of Wireless Choices Keeps Proliferating While WECA vendors have pushed very hard to position IEEE 802.11b products as the best wireless LAN choice, there are other products out there that can create buyer confusion even before IEEE 802.11g or 802.11a products appear. The HomeRF group recently moved from a 2Mbps specification to a 10Mbps specification. While the technology was designed originally for home use, its low cost and ability to handle time-sensitive traffic via prioritization could make it attractive for certain customers. Some vendors, such as Proxim, are still offering 2Mbps products that are priced well below 802.11b products and do offer the protection of IEEE 802.11 certification. At the same time, Bluetooth products are beginning to appear, and some vendors are hyping the use of small Bluetooth networks (piconets) as a low-cost LAN solution. To make matters worse, the proliferation of Bluetooth devices continues unchecked by the serious interference problem between Bluetooth devices and IEEE 802.11b LANs. The table below summarizes the various flavors of wireless LAN technology now available or available shortly. Technology Raw Speed Availability Comments IEEE 802.11b 11Mbps Available The market leader IEEE 802.11 2Mbps Available Older but very inexpensive technology HomeRF 10Mbps Available Originally designed for home and small office but does include quality of service (QoS) good for multimedia or voice traffic IEEE 802.11a 54Mbps Q1 2002 [.8p] A 5GHz frequency technology that will likely be used for high-speed backbones and low latency traffic IEEE 802.11g 22Mbps Q1 2002 [.6p] A 2.4GHz frequency technology that has the advantage of interoperability with IEEE 802.11b products, but major 802.11b vendors have not announced support HiperLAN/2 54Mbps Q1 2002 [.7p] A 5GHz technology supported by European vendors: Its physical layer is identical to 802.11a, but its MAC layer is more ATM-like with quality of service features. Bluetooth 1Mbps Available The linking of Bluetooth devices into piconets forms small networks. In addition to the expected release of both 802.11a and 802.11g products early next year, European vendors are extolling the benefits of HiperLAN/2 products that fall into the same 5GHz frequency range as 802.11a products and offer the same 54Mbps performance plus some additional features. HiperLAN/2 products are also due to ship in early 2002. The result of all the current products on the market as well as the new products due early next year is that selecting a wireless LAN product has become more complicated. Customers must consider many questions, including the following: Should I buy now or wait for lower prices early next year? If I install 802.11b networks, how will they work with higher-speed 802.11a networks? Will I have to replace any expensive access points I purchase now? Will QoS be added to 802.11b soon, or should I look into HomeRF or HiperLAN/2? When will a standard for Layer 3 security be approved? Should I chance getting locked into a proprietary product right now? Should I buy now and face the problem of interference with Bluetooth products or wait until the interference issue is solved by the standards group? Should I wait until 128-bit encryption becomes a standard rather than a proprietary product? The result of all these issues is that sales might suffer until vendors and standards groups solve these problems. Alternative View Vendors are likely to head off potential market problems by preannouncing the prices of IEEE 802.11a products and establishing a price/performance ratio that will not hurt sales of 802.11b products. Customers that really need the performance offered by 802.11a technology will pay the premium. Findings & Recommendations The IEEE 802.11b products currently dominate the wireless LAN market, but other options exist for customers, including the following: 802.11 products operating at 2Mbps Low-cost HomeRF products operating at 10Mbps Slow but low-cost Bluetooth products linked into small networks called piconets To complicate matters, the first quarter of 2002 should see the introduction of 54Mbps IEEE 802.11a wireless LAN technology as well as 54Mbps HiperLAN/2 products. Vendors also have plans to introduce 802.11g products that will offer 22Mbps performance and backward compatibility to 802.11b products. To make matters worse, there are several issues that still have not been resolved by vendors, including when standards will be finalized for enhanced security and elimination of interference between Bluetooth and 802.11b products and how 802.11a and 802.11b products will coexist on a network. Customers also are concerned about how prices will change early next year when these new products are introduced. Such customer concerns are likely to be reflected in a postponing of the decision to purchase wireless LAN technology until these problems are resolved. Giga clients should do the following: Defer purchases of wireless LANs from the fourth quarter of 2001 to the first quarter of 2002 unless there are extenuating circumstances that require immediate deployment. Waiting should result in lower prices and improved security. Get a firm commitment from a vendor that proprietary security enhancements will be upgraded to the 802.1x standard when it is finalized. Determine whether or not Bluetooth will play a role in the same environment with 802.11b technology. If so, determine policies that will keep the two technologies from being in close enough proximity to cause interference since an 802.15 specification to solve this problem has not been finalized yet. Weiterführende Informationen zu Wireless Lans sind bei der Giga Group erhältlich. Alles zu ERP auf CIO.de Alles zu Security auf CIO.de

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