James Brehm's Blog


WiMAX Quietly Invades China

16 Feb 2011 | by James Brehm
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12/05/2010

ChinaTel Group (ChinaTel) is working furiously to deploy a WiMAX network in the 3.5 GHz band across 29 markets in China, including large population areas such as Shanghai and Shenzhen. With roots and a history as a network engineering and design firm building wireless networks for Sprint Nextel Corporation and T-mobile, the company originally entered the Chinese market in 2007, rolling out commercial Wi-fi networks in Beijing to support the 2008 Olympics. Today, with aspirations at gaining millions of broadband subscribers, ChinaTel has has between 400,000 and 500,000 people paying for access to its Wi-fi network that covers parts of Beijing, Shanghai and Shenzhen.

WhyMAX?

ChinaTel’s move into the WiMAX market and away from Wi-fi has both business and technical reasons. After rolling out the Olympic Wi-fi networks, the company, through its partnership with CECT-Chinacomm Communications (which was granted spectrum licenses by the government), will build out a wireless broadband network using the 802.16e WiMAX specification.

WiMAX (Worldwide Interoperability for Microwave Access) is the IEEE 802.16 standards-based wireless technology that provides MAN (Metropolitan Area Network) broadband connectivity. Unlike Wi-fi, which has an average commercial hotspot range of 150-700 feet, WiMAX's range is typically measured in miles.

WiMAX is an Air Interface for Fixed Broadband Wireless Access Systems, also known as the IEEE WirelessMAN air interface. WiMAX-based systems can be used to transmit signals as far as 30 miles. WiMAX can offer a solution to what is normally called the "last-mile" problem by connecting individual homes' and business offices' communications.

WiMAX supports ATM, IPv4, IPv6, Ethernet, and VLAN services and can provide either traditional Time Division Multiplexed (TDM) voice or IP-based Voice, also known as Voice over IP (VoIP). WiMAX-based solutions include many other advantages, such as robust security features, good QoS (Quality of Service), and mesh and smart antenna technology that will allow better utilization of the spectrum resources. With that being said, WiMAX offers a rich choice of value added service possibilities to voice and data network service providers.

In addition, WiMAX provides an ideal wireless backhaul technology to connect 802.11 wireless LANs and commercial hotspots with the Internet.

Setup

The WiMAX-based solution is set up and deployed like cellular systems using base stations that service a radius of several miles/kilometers. Given ChinaTel’s history of deploying complex cellular networks for T-mobile and Sprint, the move to WiMAX should prove to be no problem. The most typical WiMAX-based architecture includes a base station mounted on a tower of building and is responsible for communicating on a point to multi-point basis with subscriber stations located in business offices and homes. The customer premise equipment (CPE) will connect the base station to a customer as well; the signal of voice and data is then routed through standard Ethernet cable either directly to a single computer, or to a Wi-fi hot spot or a wired LAN.

Limitations of Competing Technologies

Currently, there are 3G wireless, cable and DSL broadband access services in the Chinese marketplace. But, their practical limitations in features and deployment have prevented them from reaching many potential broadband Internet customers. Theoretically, WiMAX networks generally provide speeds that are many times that of 3G wireless networks without the delayed ping latency of 3G.

The wired broadband connection provided by cable and DSL is a labor intensive and expensive process. Traditionally, DSL can only reach about 18,000 feet (roughly three miles)-36,000 feet (roughly seven miles) from the central office switch, and this limitation means that many urban and suburban locations may not be served by DSL connectivity.

More than 20 Chinese cable operators have ISP licenses, yet very few of these deliver commercial broadband and those that do are mostly niche players. Without their own international gateway and sometimes backbone networks, cable operators have to pay large fees to telecom operators.

Another limitation of cable is that many older cable networks have not been equipped to offer a return channel and converting and deploying these networks to support high-speed broadband can be expensive.

What this all Means

Earlier this year, CNNIC (China’s Internet Network Information Center) reported that China now has over 400 million broadband users up from 100 million in 2005. (That’s roughly 1/3 of the entire Chinese population and roughly the size of the US, Canada and Mexico combined.) But when you scratch below the surface, 60% of those broadband subscribers only have 3G wireless broadband access.

While nice to have, 3G wireless broadband doesn’t provide the same quality experience that WiMAX or other broadband technologies afford. By providing WiMAX service, ChinaTel should be able to capitalize on the desire for uniform high speed connectivity.

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