WiMAX Lets Wireless Networks Extend for Miles

by Matt Gillespie


WiMAX wireless Metropolitan Area Networks (MANs), based on the IEEE 802.16 family of standards, will soon offer wireless broadband Internet access to residences and businesses at relatively low cost. The standard supports shared transfer rates up to 75Mbps from a base station, which can offer broadband access without requiring a physical 'last-mile' connection from the end customer to a service provider. Service delivery to end clients is likely to be roughly 300Kbps for residences and 2Mbps for businesses.

This technology will be particularly beneficial to many rural areas and other locations where broadband access is not currently available. The current infrastructure owned by cable providers provides coverage to only limited areas, and much of it is suited only to cable television; upgrades to make it capable of delivering broadband data service are expensive, and therefore prohibitive in low-density markets.

DSL has the limitation that end-users must be within approximately three miles of the phone company's central office or a major secondary distribution point called a Subscriber Loop Carrier. Thus, for many users, particularly those in rural locations, DSL is not available.

The superior range of WiMAX connectivity and its independence from any wired distribution medium allow it to overcome these limitations. Although the optimal range is 4-6 miles, as opposed to the 30 mile maximum range, the relatively low cost of covering a distribution area with WiMAX service, relative to cable or DSL, will be an incentive to service providers to extend coverage to new business and residential customers. Thus, while this technology will not provide universal broadband service, it should extend service areas substantially beyond their current limits.

Wireless MANs also promise to provide rapid provisioning of broadband service for businesses. Telcos routinely require several months to provide new T1 lines and other enterprise-level data connections for business customers under ideal circumstances, and installation costs tend to be quite high. The dependence on businesses of all sizes on such provisioning for mission-critical resources has grown dramatically in the past ten years. The obstacles in terms of long installation lead-times and high provisioning costs have remained relatively constant.

Paul Otellini announced at the Fall 2003 Intel Developer Forum that Intel will begin production of WiMAX silicon in 2004. Stationary broadband connectivity to businesses and homes will be provided by 802.16a (standard approved January 2003), followed by mobile access to laptops via 802.16e (standard pending). The 802.16a standard covers the frequency range of 2-11 GHz, which allows the technology to operate without line-of-sight limitations.

Opportunity for competitive advantage will arise for those developers who create applications that best take advantage of this new technology. Enterprise solutions for implementations such as utility-company field personnel, news services, and delivery drivers will be able to target a higher ratio of connected-to-unconnected user time than at present. VPN and related technologies will also need to retool to be compliant with the new standards.

Bringing Br oadband to New Markets

In many emerging markets throughout the world, wired infrastructure for the delivery of residential and business broadband does not exist or is unreliable. In order to extend services to these markets, service providers must often provide new infrastructure from the ground up, which drives the price of services up to the point where adoption is prohibitively slow. In order for those providers to show profit in an acceptable timeframe, infrastructure costs must be closely controlled. This factor is especially pronounced* in sparsely-populated areas, which are traditionally under-served by communications technology.

Wireless last-mile technologies promise to make service delivery profitable in many regions where traditional wired technologies are impractical. According to Sean Maloney, Intel executive vice president and general manager of the Intel Communications Group, a number of telecommunications carriers are considering the provision of WiMAX service in a broad range of both primary and emerging markets.

The small-business market is currently served largely by DSL, and to a lesser extent, by cable networks for broadband connectivity. In addition to the location limitations already discussed, these technologies typically provide limited upstream bandwidth, which can be a substantial limitation for many business customers, depending upon their specific needs. Those businesses that host Web-based resources or support a substantial remote-user base may find this limitation to be particularly significant. Moreover, since cable provider networks were put in place primarily to serve the cable-television market, they are not available to many commercial locations.

WiMAX provider networks provide an alternative to these distribution channels, since they are independent of existing last-mile infrastructure and they provide greater upstream bandwidth than cable and DSL. These networks are also highly scalable, since providers can add additional cells to a service area at a cost that is substantially lower than that required to extend a DSL or cable network.

On the other hand, the most profitable distribution areas for media services are generally those with the highest population densities. In the case of residential and small-business broadband, those services' areas are largely already served by cable and/or DSL. Thus, new service modalities are likely to have a hard time competing on those markets, where the customer bases are already well served. Thus, WiMAX is expected to thrive largely in rural and otherwise-underserved areas, where the profit availability for providers is relatively low, which may hamper its adoption generally.

WiMAX is Well Suited to Multiple Service Levels

One aspect of the existing 802.16a standard that will make it attractive to service providers and end customers alike is its provision for multiple service levels. Thus, for example, the shared data rate of up to 75Mbps that is provided by a single base station can support the 'committed information rate' to business customers of a guaranteed 1.5 Mbps (approximately equivalent to a T1), as well as 'best-effort' non-guaranteed 128 kbps service to residential customers.

Depending upon regional demand, it should be pos sible for providers to offer a wide variety of standard and custom service offerings. By providing flexible service and rate structures to its customers, a WiMAX provider can appeal to a wide variety of needs by means of a single distribution point.

For rural areas where the distances between customers are large, 802.16 supports 'adaptive modulation', which allows it to automatically increase effective range when necessary at the cost of decreasing throughput. Higher-order modulation (e.g., 64 Quadrature Amplitude Modulation, or QAM) provides high throughput at sub-maximum range, while lower-order modulation (e.g., 16 QAM) provides lower throughput at higher range, from the same base station.

The modulation scheme is dynamically assigned by the base station, depending on the distance to the client, as well as weather, signal interference, and other transitory factors. This flexibility further enables service providers to tailor the reach of the technology to the needs of individual distribution areas, allowing WiMAX service to be profitable in a wide variety of geographic areas.

The 802.16 standard also supports differentiated quality-of-service (QoS) to govern trade-offs between latency and error rate. This capability allows the technology to provide better support to different types of data transmissions. Most types of data transmission can tolerate a reasonably large degree of latency, but error rates must be tightly controlled. Real-time media such as voice and video transmissions, on the other hand, require low latency, but some degree of transmission error is acceptable. Thus, differentiated QoS permits a single data-transmission standard to handle all these various services effectively.

Rich Implications for Mobilized Software

By considerably lessening the limitations of limited mobile bandwidth and range, widespread adoption of wireless MANs will foster new markets for mobilized software. As business customers adopt WiMAX service, demand will grow for a wide array of mobilized business solutions, especially on the basis of the 802.16e specification, which will provide service directly to end-user mobile devices from central base stations.

Businesses will be able to provide connectivity directly to field personnel over a wide territory on a more widespread basis than has been common thus far. The high bandwidth and range of WiMax-based services, relative to other wireless technologies, is likely to create demand for mobilized software solutions in industries that currently do not make widespread use of them.

Service technicians, field sales personnel, and maintenance crews for everything from construction equipment to computer networks will be more able to access central business systems from the field. That adoption, in turn, will help to build general demand for mobilized solutions, building on the already increasing market awareness of mobilized software's desirability.

Thus, the rise of wireless MANs is expected to drive customer expectations that business solutions in general should possess mobilized capabilities. Client software increasingly must possess the ability to seamlessly accommodate sporadic connectivity, to cache relevant data from central networks, and to provide robust data synchronization with back-end systems. As customer expectations for such functionality continue to become the norm, they emerge as a locus of co mpetitive advantage for those developers and ISVs who have positioned themselves to benefit from this trend.


WiMAX promises to expand the availability of broadband service to residences and businesses that are currently under-served, including low-density rural locations in developed countries, as well as in emerging markets. It will also provide a flexible solution to end users for whom current provisioning timeframes are prohibitive, or for whom wired infrastructure is not available.

From the perspective of service providers, the WiMAX standard provides robust support for multiple service levels with a minimum of hardware requirements. The 'adaptive modulation' capability of the technology allows modulation schemes to be assigned dynamically, making automatic tradeoffs between range and throughput and increasing service levels to end-users. Flexible quality-of-service support allows carriers to tailor services for the specific needs of different media, such as voice, video, and general data, with regard to latency versus reliable packet transmission.

Developers, service operators, and hardware manufacturers must call themselves to action in building wireless broadband solutions and devices around international standards. Such standards reduce costs and foster economies of scale by removing the necessity for multiple parties to create the technology's building blocks independently. By ensuring interoperability between services and solutions from different providers, the investment risk to all concerned is also reduced.

Wireless broadband will help to drive demand for the next generation of mobilized software by increasing the implementation opportunities for solutions that function well in an environment of sporadic connectivity. Customer expectations will continue to grow around the need for software to support on-again, off-again connectivity seamlessly, and ISVs that position their products to meet those expectations stand to gain a competitive advantage in the marketplace.

Additional Resources

The following resources provide additional information about WiMAX technology:

  • WiMAX Forum* is an open group of industry leaders that "promote deployment of broadband wireless access networks by using a global standard and certifying interoperability of products and technologies."
  • The IEEE 802.16 Working Group on Broadband Wireless Access Standards* "develops standards and recommended practices to support the development and deployment of broadband Wireless Metropolitan Area Networks." Intel, the world's largest chipmaker, also provides an array of value-added products and information to software developers.
  • Intel® Software Partner Home provides software vendors with Intel's latest technologies, helping member companies to improve product lines and grow market share.
  • The Intel® Developer Zone offers free articles and training to help software developers maximize code performance and minimize time and effort.
  • Intel® Software Development Products include Compilers, Performance Analyzers, Performance Libraries and Threading Tools.
  • IT@Intel, through a series of white papers, case studies, and other materials, describes the lessons it has learned in identifying, evaluating, and deploying new technologies.

About the Author

Matt Gillespie is an independent technical author and editor working out of the Chicago area and specializing in emerging hardware and software technologies. Before going into business for himself, Matt developed training for software developers at Intel Corporation and worked in Internet Technical Services at California Federal Bank. He spent his early years as a writer and editor in the fields of financial publishing and neuroscience.