IEEE weighs WLAN enhancements

IEEE weighs WLAN enhancements

An alphabet soup of new specifications is in the works in the IEEE 802.11 Working Group, the body in charge of the popular set of wireless LAN standards generally marketed under the name WiFi. In the end the new capabilities should make the technology easier to use, a working group executive said last week.

A "task group" studying how to guarantee good enough quality of service (QoS) for voice, video and other sensitive applications over wireless LANs reached a rough consensus earlier this month over which mechanism should be used to ensure that quality, said Al Petrick, vice chairman of the working group, at the Communications Design Conference in San Jose. Other active groups are considering enhancements to security, roaming, quality of service and other aspects of IEEE 802.11 networks, he said.

Meanwhile, "study groups" surrounding 802.11 are looking farther out at how to manage wireless LANs, push them further up in bandwidth, and figure out how they can fit in with myriad other wireless technologies. Those groups may recommend that the 802.11 working group form new task groups to develop specifications.

The new specifications may not lock into 802.11 everything that all users need, but they are steps in the right direction, according to Gerry Purdy, principal analyst at MobileTrax.

Businesses and consumers are rapidly adopting IEEE 802.11b wireless LANs, and faster products recently hit the market based on the IEEE 802.11a specification. The wireless LANs have drawn interest for packet-based voice calling and other applications as well as Internet-access sharing and traditional data LANs. However, they are still perceived as relatively insecure, and despite the availability of some public "hot spots", it is still unclear whether and how wireless LANs will fit in with service provider networks.

This month, a study group was formed to examine how 802.11 networks may interoperate with other wireless networks, such as GSM (Global System for Mobile Communications), 3G (third-generation) mobile wireless services and the European HiperLAN 2 standard. The group, called WIG (Wireless Interworking Group), will consider issues such as unified authentication across networks using the different technologies, Petrick said.

This work could be critical, according to Purdy. "Eventually, what you want is an ability to have seamless roaming on both wireless voice and data devices. The user says, 'just stay connected'. What we don't have is a mechanism for doing that," Purdy said.

Stronger tools for securing wireless LANs will probably hit the street in products in the second half of next year, after Task Group I completes its IEEE 802.11i specification, according to Petrick. The most recent draft of that specification would require 802.11 equipment to support three algorithms for encrypting wireless LAN traffic: TKIP (Temporal Key Integrity Protocol), WRAP (Wireless Robust Authenticated Protocol) and CCMP (Counter with Cipher Block Chaining Message Authentication Code Protocol). It will also require "hooks" into the IEEE 802.1x standard for controlling access to a network.

TKIP and WRAP can be added to an existing 802.11 product by a software upgrade alone, according to Petrick. A "snapshot" of the TKIP mechanism while it was in development, called SSN (Safe Secure Networks), has already been adopted by the WiFi industry group because of the perceived urgency of the need for greater security, he added.

The three options called for in the latest 802.11i draft would represent a leap ahead in security for home users, though equipment makers who focus on enterprises probably will continue to build in additional security features, Purdy said.

The closely watched Task Group G, which is working out the 802.11g standard, is set to finish its latest round of voting at a November meeting in Kauai, Hawaii. The group is studying wireless LANs that deliver as much capacity as 802.11a, which delivers up to 54Mbps, but remain compatible with both that standard as well the more widely deployed 11Mbps 802.11b technology. Like 802.11b gear, equipment built to the new standard will use the 2.4GHz radio spectrum. Products compliant with the final 802.11g standard are likely to hit the market in the second half of next year, Petrick said.

After Task Group G's work is done, Petrick expects members to shift their focus to the 5GHz High Rate Study Group, which has already been formed to study how to increase the throughput of 5GHz wireless LANs beyond even the speed now offered on 802.11a networks.

Roaming between wireless LANs within an enterprise or in public hot spots may become easier after approval of specifications being considered by Task Group F. These specifications will define how access points from different vendors exchange information about clients and user identities. That should allow for seamless roaming between areas served by any vendor's access point. In addition, any access point should be able to understand information from another access point about a user that has been authenticated, so users should be able to roam between hot spots operated by different service providers without having to re-authenticate themselves. That could allow for a single, shared authentication scheme shared among service providers.

Products that comply with Task Group F's specifications should hit the market in the second half of 2003, Petrick predicted.

Task Group E is working to define specifications for ensuring the quality of service (QoS) required for delay-sensitive types of communication such as voice, video and multimedia. After long debate between participants seeking specifications best suited to the enterprise and participants seeking those best suited to the home, the group this month reached a consensus, he said.

In addition to voice, the QoS specification should support smooth transmission of MPEG (Moving Picture Experts Group) video and provide wireless extension of multimedia being sent between devices using the IEEE 1394 standard, also called FireWire. Although no 802.11 standard can carry on the high bandwidth of 1394, with these new QoS specifications the WLAN will let 1394 devices send their traffic wirelessly over short distances.

Petrick expects the earliest products, which may not comply with the final standard, to come onto the market in the second half of 2003. Standards-compliant products should hit the market by the first quarter of 2004, he added.

The QoS specification may help pave the way to IP (Internet Protocol) phones that aren't tethered to an Ethernet cable, giving users in an office greater mobility, Purdy said. As chip costs shrink, wireless LAN hardware may later be integrated into mobile phones, allowing users to make calls outdoors using a carrier network and switch over to LAN-based IP telephony inside an office, slashing a company's mobile phone bills, he added.

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