Single wireless
standard needed

Bluetooth and Home RF are unsuitable alternatives for 802.llb.

Wireless local area networks (WLANs) are widely used today in such markets as education, healthcare and manufacturing. Beyond these markets, WLANs are quickly moving into new areas, as well, including retail, hospitality, government and transportation.

What has led to the growth of wireless LANs? In addition to increased flexibility, better performance and lower costs, the momentum can be traced back to the publication of one single document—the Institute of Electrical and Electronics Engineers’ (IEEE) 802.11b—standard. This move toward standardization, combined with vendor cooperation, participation in interoperability labs and the Wi-Fi certification process of the Wireless Ethernet Compatibility Alliance (WECA), have all contributed to WLAN growth. 
Recently, two new wireless technologies have emerged to compete with 802.11b—Bluetooth and HomeRF. These new technologies increase the choices, and possibly the complexity, for enterprises faced with choosing a wireless product.

A continued focus on standardization will foster one universal standard for wireless technology, leading to global acceptance and growth. Examining the differences between the 802.11b standard and Bluetooth and HomeRF technologies, might help determine which one could become the single worldwide standard for wireless.

The 802.11b standard delivers ethernet-like 11 Mbps wireless connectivity, often referred to as high rate. Backed by many of the major vendors in the networking arena, 802.11b-compliant access points and PC cards enable wireless connectivity for mobile users within a building or campus environment. This 11 Mbps standard marks a significant jump in performance from the previous 2 Mbps standard.

ADVANTAGES OF 802.11b

The 802.11b standard offers a wide coverage range and solid performance. In many cases, users can roam approximately 400 feet from the access point, with performance varying relative to how close users are to the access point. For example, users within 50 to 100 feet of the access point typically find performance in the 11 Mbps range, while those located 350 to 400 feet could get about 2 Mbps.

Another advantage of 802.11b is that the transition between performance levels is seamles. As users roam they receive the benefits of mobility and speed while roaming throughout the coverage area. 802.11b networks offer good scalability, as well, with the ability to add hundreds, or even thousands, of end-users by installing more WLAN access points. Security, a common user concern, is addressed by encryption features offered at the 40-bit level, and even the 128-bit level by some vendors today.

802.11b has made significant progress in interoperability. Several vendors have recently participated in interoperability labs, such as the independent lab at the University of New Hampshire, and in the Wi-Fi certification process. In addition, organizations such as WECA and the Wireless Ethernet Alliance (WLANA) further encourage vendor interoperability, and actively promote and support 802.11b through their members.

Bluetooth was created around the concept of a wireless personal area network (PAN), with the goal of enabling wireless connectivity between personal computers and portable hand-held devices, such as personal digital assistants, cell phones and digital PCS phones. Although Bluetooth is not a standard at this point, it could play an important role in the wireless market because of the growth of hand-held devices, especially if these devices offer Internet access.

Bluetooth offers range (30 feet) and scalability (80 ad hoc nodes) more suited to the PAN, and should not be thought of for LAN scenarios. The strength of Bluetooth’s original pricing structure was its target of around $5 per user. With current technology, however, its pricing ranges are significantly higher than expected.

WIRELESS FOR THE HOME

The HomeRF Working Group (HRFWG) and HomeRF— formed in 1998 to develop wireless connectivity between PCs and consumer-oriented electronic devices for the home—expected that the 802.11 standard was too focused on the needs of enterprise environments.

The HRFWG created a wireless specification for homes called shared wireless access protocol (SWAP). HomeRF faces two challenges: 1) the range of its products (especially at higher bandwidths) and 2) regulatory approval. HomeRF’s 1.6 Mbps products were barely reaching the ranges of its 802.11b competitors, and SWAP was not previously approved for high-rate radio transmission. In August 2000, the FCC ruled to allow 10 Mbps rates for HomeRF.

In all, standardization and interoperability are the keys to wide acceptance of any new technology, including wireless. While HomeRF and Bluetooth offer benefits to home and mobile users, they potentially negate the benefit of true user mobility from the office to the home. Consumers do not want to have different technologies for the home and the office.

The ideal scenario is one technology to seamlessly operate between the home and office. Therefore, Bluetooth and HomeRF could further segment and cloud an already confusing wireless landscape. By actively promoting and pursuing one standard, the established 802.11b standard, wireless LANs will eventually move outside of the office and campus, and migrate into new frontiers, including the home and personal network.

Durand is a technical architect and Schwartz a wireless engineer at Enterasys Networks, Rochester, NH. Comments for publication should be sent to guest@comnews.com