



Originally called WirelessMAN, WiMAX (Worldwide Interoperability for Microwave Access) is the El Dorado of wireless data transmission, with versions of it providing both high-bandwidth point-to-point links and mobile cellular-type access. It’s potentially a viable wireless alternative to cable and DSL. In the last 12 months, several WiMAX trials and actual commercial networks have been initiated worldwide for last mile broadband connectivity for both the consumer and enterprise segments. Until now, however, America has lagged behind the rest of the world in terms of WiMAX build-out and adoption. This article originally appeared in the October issue of Internet Telephony magazine.Originally called WirelessMAN, WiMAX (Worldwide Interoperability for Microwave Access) is the El Dorado of wireless data transmission, with versions of it providing both high-bandwidth point-to-point links and mobile cellular-type access. It’s potentially a viable wireless alternative to cable and DSL. In the last 12 months, several WiMAX trials and actual commercial networks have been initiated worldwide for last mile broadband connectivity for both the consumer and enterprise segments. Until now, however, America has lagged behind the rest of the world in terms of WiMAX build-out and adoption.

The WiMAX standard originated with the IEEE 802.16 wireless broadband committee. Conformance and interoperability testing was formalized with the industry group known as the WiMAX forum (founded in 2001) formulated a set of product guidelines based on the 802.16 standards or “WiMAX profiles”.

At the moment there are two versions of WiMAX: Revision D is based on the IEEE 802.16-2004 standard. It is only for fixed applications. Revision E, based on IEEE 802.16e-2005, supports fixed and mobile applications and has a more sophisticated radio interface. These two forms of WiMAX are incompatible, so, given that the future of telecom is definitely rooted in mobility, much of the wireless industry has only paid lip service to Revision D and has instead focused on developing products adhering to Revision E (802.16e).

At the moment, Pakistan enjoys the world’s largest WiMAX network. Wateen Telecom rolled out WiMAX in 17 cities throughout Pakistan on a platform built with Motorola equipment.

Indeed, Motorola is one of the companies at the forefront of WiMAX development. Motorola’s Fred Wright, Senior Vice President for Cellular Networks & WiMAX, says, “We now have many commercial contracts for WiMAX in a number of markets around the world. A few months ago, we were in a kind of transition stage. We’re now moving from the trial phase with a number of customers to commercial contracts, and we have a number of systems under construction or we will be getting them under construction fairly quickly. Today, we also have, in general, commercial service with a number of customers around the world. Customers are building out networks such as Embratel in Brazil, Axtel in Mexico, and Wateen Telecom in Pakistan is expanding and reinforcing the capacity of their network. We’re building with a telco in Saudi Arabia too, as well as Mena Telecom in Bahrain. We have project after project. The technology is real, it works. We have commercial grade software out there in the field that is supporting customers. And we periodically win new contracts with new customers.”

“The WiMAX Forum has a certification program that subjects products to intensive, rigorous testing to assure everyone that they have the ability to interoperate with WiMAX devices from other vendors that have the same certification,” says Wright. “In June, Motorola’s WiMAX WAP 25400 base station passed the interoperability and conformance tests and thus received the WiMAX Forum Certified seal of approval for operation. So we now have certification on our most popular base station product, called a Diversity Access Point, for customers around the world. This is the access point or the base station that has the power amplifiers and antennas combined into a single unit to make it nice and compact. It has a minimal footprint, which means that it only needs a small common equipment cabinet that sits at the base of the tower, that can be mounted on a wall or a post or potentially placed inside of a building.”

“Right now we also in the process of getting a number of our Customer Premise Equipment [CPE] units going through the certification process,” says Wright. “We have both indoor and outdoor customer premises equipment that we sell around the world. We’re just about commercially ready with a PC dongle, a USB connector that plugs into a PC and provides full mobile WiMAX functionality. We’ve gone through all of the shakedown tests and so forth. That product is now in a state where it should be commercially ready very soon.”

“So, Motorola has a good portfolio, not only of base station products operating in the 2.3, 2.5, 3.5 GHz frequency bands, but we also have a fairly significant variety of customer premise equipment, both indoor and outdoor varieties that come with different features. Some of them are data-only, some of them also have a voice port in them, so you can just plug an RJ-11 connector from a desktop phone into the CPE unit and you can do VoIP calling on the customer’s network. Of course, you’ve got to connect to a VoIP switch, which is part of what we’re interfacing into with various customers. Our Motorola wi4 WiMAX CPEi 750 Desktop CPE won TMC’s 2008 WiMAX Distinction Award.”

Motorola’s rival, Nortel, is also aggressively pursuing early market opportunities for WiMAX. For example, they recently announced that Comstar United Telesystems, Russia’s leading integrated telecom service provider, has selected Nortel’s WiMAX solution to provide wireless broadband in Moscow, which has the highest penetration of mobile phone subscribers of any major Russian city (at over 150 percent) and the highest Internet penetration. (Rethink Research Associates Ltd. estimates that the number of WiMAX subscribers in Russia will grow to 1.7 million in 2010 and 4.3 million 2012.)

The Nortel WiMAX solution sold to Comstar includes the WiMAX BTS 5020 (mobile WiMAX base station), compliant with WiMAX Forum and RosSvyaz standards. Comstar will initially deploy over 160 mobile WiMAX (802.16e) base stations (BTS 5020). The network will also include Nortel’s the Access Services Network Gateway (ASG) 5100, devices such as USB adapters, indoor and outdoor gateways, Business Support System (BSS) and Operational Support System (OSS) platforms as well as Nortel Global Services for WiMAX such as network design and training.

This is Nortel’s first mobile WiMAX win in Russia and should be a major boost for Nortel’s 4G strategy, which includes a strategic WiMAX agreement with Alvarion, is helping Nortel to bring WiMAX to market faster to customers.

Is Good Old Voice the WiMAX “Killer App”?

Carriers and service providers have been searching for the next “killer app” for years. Voice, however, remains the time-honored moneymaker. WiMAX providers have found that voice doubles the average revenue per user, gives the service provider a bundled and branded service, broadens their market reach and decreases their cost to acquire new customers. This probably helps to explain the popularity of Alianza’s hosted voice platform among WiMAX service providers, which gives service providers the ability to offer a wide range of voice features and functions to small business and residential users - up to 120 different functions. Since it is a fully integrated SaaS (Software as a Service) platform with a simple interface, providers can be up and running in 30 to 90 days.

Moreover, Alianza’s SaaS-based pricing model eradicates capital expenditures and slashes operating expenses. The simple plug & play implementation also eliminates the need to recruit an engineering team capable of building, integrating, and maintaining a tier-1 platform. It gives providers the ability to create custom products tailored for specific markets niches (e.g., residential, SMBs). The service provider can provision directly using proprietary telecommunications carriers. Thus, the service provider can focus on core competencies and increasing revenue.

Alianza now offers services in North America with plans to expand throughout South America, Europe, and APAC over next 6-18 months. Recent customers include DigitalBridge Communications and MVS in Mexico.

Getting the Nitty-Gritty Right

Everything about WiMAX is more sophisticated than, say WiFi. Researchers and service providers soon realized that high-performance, flexible yet cost-effective antenna solutions capable of handling coverage and interference issues were necessary for the successful deployment of WiMAX. Companies such as PCTEL, Inc. have thus stepped forward with their innovative antenna solutions and software-based radios. Its portfolio includes a broad range of antennas for WiMAX, Land Mobile Radio, GPS, telemetry, RFID, WiFi, indoor cellular, and mesh networks. PCTEL’s products are sold worldwide through direct and indirect channels.

PCTEL is now working with several leading WIMAX OEMs to develop both point-to-point and point-to-multipoint antenna solutions. PCTEL has also devised scanning solutions to test for coverage and identify problem areas in a network.

The more sophisticated the antenna and radio interface demanded by WiMAX also results in a more sophisticated testing regimen. As Graham Celine, Senior Director of Marketing at Azimuth, says, “The key component from our perspective is that wireless technology – and it really doesn’t make any difference what particular wireless technology – went through a paradigm shift when it transitioned from a single antenna to multi-antenna architecture. Doing so made it more complex. This has happened in many different technologies. In fact, it started in the WiFi realm when it moved from the single antenna 802.11a/b/g to the multi-antenna 802.11n. Similarly, in the WiMAX space, 802.16 has always been defined from pretty much Day One as multiple antenna-capable, with the first standardization of the multi-antenna form being 801.16e, or the ‘Mobile WiMAX’. As you look forward, the cellular technologies such as GSM and CDMA are essentially converging. They managed to say apart in the 3G world with UMTS and 3GPP2 and EVDO type of technologies, but as mobile is moving to 4G today, such as the upcoming WiMAX and LTE, once again we’ve moved back to multi-antenna form factors.”

“That’s where we’ve really been involved in WiMAX,” says Celine. “We’re a test equipment company and so our involvement consists of determining how we can support the companies that are developing things such as base stations or subscriber stations to properly validate these products before they’re rolled out into the field. We figure out how to save providers time, money and time-to-market in producing these products. The biggest challenge for providers is that there’s a real-world environment which involves multiple signal paths. If you have a mobile or stationary multi-antenna device with two antennas and a multi-antenna base station with two antennas, the signal paths multiply in both directions. In the real world, that changes. Each one of those signals goes through multiple paths and the signal gets replicated through reflection and is subject to fading in that it varies in signal strength because of those reflections and other disturbances in the path.”

“That’s why we’ve developed a channel emulator which essentially connects between the base station and the subscriber station and, through statistical modeling, recreates those over-the-air conditions,” says Celine. “That really allows a vendor to do robust testing in the lab, so they can do product or radio conformance testing, or just straight functional testing. It could be throughput performance testing, or most important, interoperability testing. This can all now be done in a real-world scenario without ever having to leave the test lab. They can run this for many hours. They can create different statistical models and they can run them for a relative long period of time. Then if they detect any discrepancies in the device behavior, they can go back and they can repeat precisely the same situation where it happened.”

WiMAX When?

While Pakistanis luxuriate in WiMAX wireless broadband, we Americans await the big commercial rollout of Sprint-Nextel’s Xohm WiMAX service. WiMAX is appearing here and there in North America, and the ball is slowly beginning to gather momentum. Still, I’m itching to trade in my EVDO card.

Companies Mentioned in this Article:

Edited by Greg Galitzine