A generation raised on the practice of instant messaging, Google searching and instant access to all types of media has created a demand for personal broadband to be available not only at fixed locations, but also wherever users might be.

The concept of personal broadband - the ability to take your high-bandwidth connection with you wherever you go - has the potential to transform the way we interact and conduct business. This capability is being made possible by the convergence of a number of technical and social factors. A generation raised on the practice of instant messaging, Google searching and instant access to all types of media has created a demand for this type of interaction to be available not only at fixed locations, but also wherever users might be. At the same time, the advent of WiMAX and WiFi technologies coupled with a high-bandwidth, flexible IP-based transport infrastructure has created the ability to satisfy that demand at cost points that are economically attractive.

As is usual with such revolutions, the solution does not spring fully formed, but various aspects of it become embedded in new networks with increasing capability available in each new incarnation.

The initial instance of this evolution began with WiFi hot spots, typically tied to specific wired locations, such as coffee shops or airports.

This allowed a degree of portability of one's broadband access but was strictly limited in scope. This concept has been expanded in recent months to include citywide networks such as Philadelphia, San Francisco, Anaheim, Calif., and many others. These networks provide ubiquitous access with minimal to zero user access fees; however, they do not provide true mobility due to the lack of a mechanism for seamless handoff between WiFi access points.

The path to true broadband mobility has followed two main routes. The first is the evolution of the traditional cellular network to provide increasing data bandwidth from a few bits per second with wireless application protocol (WAP) or enhanced data rates for GSM evolution (EDGE) enabled handsets, to a few hundred kilobits per second with evolution-data optimized (EVDO) or high-speed downlink packet access (HSDPA), to the promise of millions of bits per second with the eventual long-term evolution of the 3G standard (3G LTE). Alternatively, WiMAX, which began as a fixed broadband access technology, has recently added features to enable mobility. WiMAX can deliver capacity similar to the 3G LTE but is being deployed in networks now, while the 3G LTE is not expected to be available for at least two years.

Either technology path enables a broad spectrum of new applications from mobile video to interactive gaming to data sharing. The networks required to deliver this type of service are significantly different from cellular networks deployed today. When the bandwidth per end-user is low, the base station density is determined by the radio frequency (RF) signal strength.

As the capacity per end-user increases, the limiting factor becomes the spectral efficiency of the access spectrum. This reduces the area that can be covered by each base station, significantly driving up the base station density.

The result is a higher percentage of base station sites that are not served by fiber. At the same time, the bandwidth each base station generates has increased more than 10-fold, outstripping the capability of leased T1 lines.

The net result is that for these networks to be built they require a high-capacity, wireless backhaul infrastructure.

The requirements on this backhaul network are similar, regardless of the radio access technology - IP-based, highly scalable, low latency and able to support point-to-point, ring and mesh network topologies.

The capital expenditure on the backhaul portion of the network represents a significant percentage of the total network spend and is a key technology decision when designing such networks.

Blurring the Lines
The ability to have such a personal broadband connection will result in a change in the way we purchase telecommunications services.

With the integration of multimode ICs into computers and handheld devices that support WiFi and WiMAX interfaces, new service models will emerge. Rather than have separate fixed and mobile devices, we will migrate to a single service that we can use on multiple devices whether we are at home, at the office or moving about.

The service will be tied to a person, rather than to a location, resulting in significant churn in the customer base of all telecom providers and a blurring of the distinction between mobile and fixed-access providers. This dislocation represents both an opportunity and a challenge to all the players.

Real world examples of these evolving networks are being deployed worldwide. ClearWire in the United States and Europe has deployed pre-WiMAX networks in more than 30 cities for residential Internet access and has stated plans to deploy mobile WiMAX-compliant networks in 2007. Sprint has chosen mobile WiMAX as the technology of choice for its 4G rollout. It has stated that it will spend several billion dollars on network deployment over the course of the next few years.

T-Mobile has spent more than $4 billion (U.S.) acquiring access spectrum in the recent advanced wireless services auction and plans to spend billions more in building out a nationwide HSDPA network using that spectrum. WiMAX spectrum auctions are being held throughout Europe and Asia, paving the way for new network deployments in these regions, as well.

Municipal and county network deployments have also been accelerating, with Earthlink being a major player in North America and individual county/regional councils building their own networks in the U.K. and France. These networks are targeted more at the ubiquitous availability of wireless broadband access, rather than mobility. They are often funded by taxpayer money and are used to accelerate economic development by improving the quality of life or by enhancing broadband access for corporate customers. As a side benefit, they can be used to reduce the telecom costs for the government and emergency services in the municipality, as well.

Personal broadband, while not completely a reality yet, is very near. This has been enabled by new standards such as WiMAX and the ongoing technology-driven reduction in the cost per bit of all telecom services. Although the precise implementation will vary, the net result will be a dramatic change in the way we purchase and use telecom services. Dislocations such as this always create opportunity for new entrants and risk for incumbents, with the net result being richer services for the end-user.   VTR_US

Alan Solheim is vice president of product management at DragonWave, a provider of wireless metro Ethernet networks based in Ottawa, Ontario. Contact him at This e-mail address is being protected from spam bots, you need JavaScript enabled to view it or 613-599-9991.