WiMax -> What is WiMax (Part-I)?

WiMAX is a wireless industry coalition whose members organized to advance IEEE 802.16 standards for broadband wireless access (BWA) networks. WiMAX 802.16 technology is expected to enable multimedia applications with wireless connection and, with a range of up to 30 miles, enable networks to have a wireless last mile solution.

WiMAX was formed in April 2001, in preparation for the original 802.16 specification published in December of that year. According to the WiMAX forum, the group's aim is to promote and certify compatibility and interoperability of devices based on the 802.16 specification, and to develop such devices for the marketplace. Members of the organization include Airspan, Alvarion, Analog Devices, Aperto Networks, Ensemble Communications, Fujitsu, Intel, Nokia, OFDM Forum, Proxim, and Wi-LAN.

WiMax -> Why WiMax

The hot network technology is WiMax, an informal term that covers two emerging broadband wireless standards for metropolitan-area networking. WiMax promises alternate routes to land lines for disaster recovery and relief from the price and service tyranny of the incumbent local-exchange carriers. It also has a compelling high-speed mobile component.

WiMax has the potential for what Carlton O'Neal, vice president of marketing at Tel Aviv-based broadband wireless manufacturer Alvarion Ltd., describes as "high-quality broadband everywhere that mirrors your connectivity experience in the office."

To the casual observer, WiMax backhaul services might not seem substantially different from today's broadband wireless access (BWA) services, though speed and coverage range are expected to improve. However, having standards for non-line-of-sight (NLOS) BWA products will create economies of scale and vendor interoperability, which should help WiMax-based services proliferate beyond the niches where BWA services can currently be found. This means that the benefits of BWA as a land-line alternative should theoretically become available to more sites and users.

"Fixed" access services and products will emerge in early 2006, followed by the mobile flavor a year or so later. There are two corresponding WiMax standards:

• IEEE 802.16-2004 for fixed point-to-point and point-to-multipoint wireless access. It's akin to a faster, airborne version of Digital Subscriber Line (DSL) or cable-modem services and became the industry's first NLOS BWA standard last June.
• IEEE 802.16e, for mobile wireless access from laptops and handhelds. It's analogous to a faster version of third-generation telecommunications technology. WiMax proponent Intel Corp. has promised 802.16e-enabled laptops by early 2007.
  

Intel is also involved in the 802.16-2004 standard effort. The vendor says it's providing silicon to Alvarion, Proxim Corp. and Redline Communications Inc., which are manufacturing last-mile fixed products for the carrier market.

The technologies based on the two standards operate in licensed and unlicensed frequency bands below 11 GHz. The standards are being overseen from a market-acceleration standpoint by a 230-company consortium called the WiMax Forum.

Enterprise Impact

WiMax is being deployed from the top down as a carrier technology first, which means that schedules for service availability are dependent on widespread testing and buy-in. WiMax product standards certification and interoperability testing, overseen by the WiMax Forum and to be conducted by independent test lab Cetecom Spain in Malaga, is slated to begin in July.

Once services become available, growing business sites should gain inexpensive broadband access with speeds between T1 and T3 line capabilities. And because they're airborne, these services can be quickly deployed—often in a day's time—and bypass lengthy ILEC lead times.

"Every enterprise struggles with the cost of [local] access, which is often 40%" of a telecommunications bill, says David Willis, an analyst at research firm Meta Group Inc. "The natural monopolies have starved out local competition. But WiMax doesn't require dealing with lobbyists or tariffs."

Adds Alan Menezes, vice president of marketing at Aperto Networks Inc., a maker of BWA products in Milpitas, Calif., "Enterprises gain alternatives to the [regional Bell operating companies] and backups to terrestrial T1 and fiber links that can be cut at the same time." In addition, WiMax comes ready-made with provisions for quality of service, so many prestandard services already support voice over IP, unlike many DSL and cable-modem options.

And standards-based technology should drive down customer premises equipment (CPE) costs for fixed connections, from about $800 today to $300 to $400 in 2006 or 2007, says Bob Egan, president of Mobile Competency Inc., a consultancy in Providence, R.I. Meta Group is even more bullish: Willis says he expects WiMax CPE to drop to $70 by 2007.

Finally, businesses can buy WiMax-certified products to install in their campus-area networks as alternatives to private fiber connections and more-complex wireless bridging options.

GSM -> GSM Vs CDMA

One of the most contentious battles being waged in the wireless infrastructure industry is the debate over the efficient use and allocation of finite airwaves. For several years, the world's two main methods -- Code-Division Multiple Access (CDMA) and Global System for Mobile communications (GSM) -- have divided the wireless world into opposing camps. Ultimately, the emergence of a victorious technology may owe more to historical forces than the latest wireless innovation, or the merits of one standard over the other.

CDMA'War II Foundationss World

CDMA, put into an historical context, is a recently patented technology that only became commercially available in the mid-1990s, but had its roots in pre-World War II America.In 1940, hollywood actress turned inventor, Hedy Lamarr, and co-inventor George Antheil, with World War II looming, co-patented a way for torpedoes to be controlled by sending signals over multiple radio frequencies using random patterns. Despite arduous efforts by the inventors to advance the technology from experiment to implementation, the U.S. Navy discarded their work as architecturally unfeasible. The idea, which was known as frequency-hopping, and later as frequency-hopping spread-spectrum technology (FHSS), remained dormant until 1957 when engineers at the Sylvania Electronic Systems Division, in Buffalo, New York took up the idea, and after the Lamarr-Antheil patent expired, used it to secure communications for the U.S. during the 1962 Cuban Missile Crisis. After becoming an integral part of government security technology, the U.S. military, in the mid-80s, declassified what has now become CDMA technology, a technique based on spread-spectrum technology.

What interested the military soon caught the eye of a nascent wireless industry. CDMA, incorporating spread-spectrum, works by digitizing multiple conversations, attaching a code known only to the sender and receiver, and then dicing the signals into bits and reassembling them. The military loved CDMA because coded signals with trillions of possible combinations resulted in extremely secure transmissions.

Qualcomm, which patented CDMA, and other telecommunications companies, were attracted to the technology because it enabled many simultaneous conversations, rather than the limited stop-and-go transmissions of analog and the previous digital option.

CDMA was not field tested for commercial use until 1991, and was launched commercially in Hong Kong in 1995. CDMA technology is currently used by major cellular carriers in the United States and is the backbone of Sprint's Personal Communications System (PCS). Along with Sprint, major users of CDMA technology are Verizon and GTE.

Advantages of CDMA include:

• Increased cellular communications security.
• Simultaneous conversations.
• Increased efficiency, meaning that the carrier can serve more subscribers.
• Smaller phones.
• Low power requirements and little cell-to-cell coordination needed by operators.
• Extended reach - beneficial to rural users situated far from cells.
  

Disadvantages of CDMA include:

• Due to its proprietary nature, all of CDMA's flaws are not known to the engineering community.
• CDMA is relatively new, and the network is not as mature as GSM.
• CDMA cannot offer international roaming, a large GSM advantage.

The Euro-Asian Alternative: GSM

Analysts consider Qualcomm's major competitive disadvantage to be its lack of access to the European market now controlled by Global System for Mobile communications (GSM). The wireless world is now divided into GSM (much of Western Europe) and CDMA (North America and parts of Asia).

Bad timing may have prevented the evolution of one, single global wireless standard. Just two years before CDMA's 1995 introduction in Hong Kong, European carriers and manufacturers chose to support the first available digital technology - Time Division Multiple Access (TDMA). GSM uses TDMA as its core technology. Therefore, since the majority of wireless users are in Europe and Asia, GSM has taken the worldwide lead as the technology of choice.

Mobile Handset manufacturers ultimately split into two camps, as Motorola, Lucent, and Nextel chose CDMA, and Nokia and Ericsson eventually pushed these companies out and became the dominant GSM players.

Advantages of GSM:

• GSM is already used worldwide with over 450 million subscribers.
• International roaming permits subscribers to use one phone throughout Western Europe.
• CDMA will work in Asia, but not France, Germany, the U.K. and other popular European destinations.
• GSM is mature, having started in the mid-80s. This maturity means a more stable network with robust features. CDMA is still building its network.
• GSM's maturity means engineers cut their teeth on the technology, creating an unconscious preference.
• The availability of Subscriber Identity Modules, which are smart cards that provide secure data encryption give GSM m-commerce advantages.

In brief, GSM is a "more elegant way to upgrade to 3G," says Strategis Group senior wireless analyst Adam Guy.

Disadvantages of GSM:

• Lack of access to burgeoning American market.

Conclusion

Today, the battle between CDMA and GSM is muddled. Where at one point Europe clearly favored GSM and North America, CDMA, the distinct advantage of one over the other has blurred as major carriers like AT&T Wireless begin to support GSM, and recent trials even showed compatibility between the two technologies.

GSM still holds the upper hand however. There's the numerical advantage for one thing: 456 million GSM users versus CDMA's 82 million.