Radio via Wimax

Apr 1, 2007 12:00 PM, By Kevin McNamara, CNE

Occasionally there is the promise of a new technology that guarantees to change the way we do business or perhaps even change our lives. Consider what we did before the cell phone became popular or, for those in my age bracket, before we had hundreds of TV channels instead of just three. We are getting ready to witness another such event with the introduction of a wireless standard called the Worldwide Interoperability for Microwave Access, also known as Wimax, also known as IEEE 802.16x.

The previous standard, 802.16d-2004, provided Wimax as fixed point-to-point systems. The standard was expanded in 2005, with the current 802.16e-2005, adding operation in non line-of-sight applications, such as mobile applications.

Wimax provides a wide range of wireless connectivity options that might soon replace more well known standards such as Wi-fi, and third generation wireless telephony technologies such as GSM or UMTS. The data throughput of Wimax will vary with the amount of bandwidth available and can operate with delivery systems that work in as little as 1MHz or over 50MHz of bandwidth. However, even systems operating with different delivery platforms will still be compatable, which is perhaps the biggest advantage of Wimax.

It is not unusual for technologies to evolve and improve with the availability of new hardware, but what makes Wimax particularly interesting is that it will become the delivery method of choice for the advanced wireless services (AWS) that are in the beginning stages of deployment in the United States.

How could this affect traditional broadcasting? In the same vein that satellite radio has become an alternative delivery medium for programming, thus creating a new competitor in essence, the AWS could form a nearly perfect delivery platform that can provide a wide range of audio, video, data and telephony services. Investment insiders call this capability the Triple Play or Quadruple Play, which explains the price being paid for the FCC licenses recently auctioned.

Communication advantage

Unlike terrestrial or satellite broadcasting, Wimax provides a true two-way platform that not only has the capability of fixed broadcasting to a particular market, but will also provide fully bi-directional access from subscribers from fixed and mobile locations.

Another reason for the predicted success of the Wimax platform is in a networking protocol called IMS or the IP Multimedia Subsystems. The basic concept of IMS is that an IP-based platform can access a wide range of dissimilar networks such as Wi-fi, DSL, cellular, voice over IP and Internet Protocol TV.

Once the services are deployed subscribers will need the appropriate customer premise equipment (CPE), similar to a cable TV decoder. That interface will likely serve every communication need the average household uses: telephone, Internet access, video and audio services. Sounds pretty good, right? That the same service also can provide the same services in a mobile environment, like a cell phone on steroids. Imagine having all of the services you enjoy at home in the car.

Wimax is not only for the home, it can also provide high-speed data services to businesses. The nature of the technology makes it a perfect solution for the last-mile problem, where traditional wired services can be provided within a short distance of a subscriber, but there are inadequate facilities to deliver directly to a residence or business.

Wimax vs. Wi-fi

The differences between Wimax and Wi-fi are significant. Data throughput for Wi-fi has improved significantly during the past few years from 2Mb/s to the current 54Mb/s and provides a range of about 300 feet; by contrast, Wimax data throughputs exceed 75Mb/s at a range of about six miles. The range that Wimax can operate is predicated by its frequency of operation, height and antenna configuration; however, in practice, Wimax will be deployed similarly to that of a cellular mobile telephone network, where a number of sites are placed within a metro area to fill the entire market. The sites will also hand off to each other, thus providing a seamless user experience to mobile customers.

Fixed applications

Wimax is also a natural replacement for any service that is currently supplied by a wired medium such as telephone and cable, in effect bypassing the local cable or public switched network. Wimax networks will be designed similar to traditional cellular networks, using several nodes that will cover a desired footprint. Each node is fully meshed with surrounding nodes. This mesh concept provides a higher level of availability or reliability than most current systems. Consider a business that needs to connect two separate buildings with a high-bandwidth connection. If a Wimax network covers these buildings, it would be a simple matter of adding the CPE and creating the appropriate IP port.

Mobile applications

Current mobile telephony technologies provide poor to adequate data services. The third generation technologies, including UMTS, CDMA2000 and EVDO, have greatly improved throughput and reliability, but it is in the fourth generation of mobile technologies where Wimax will be implemented. All of the cellular carriers have entered into agreements with equipment suppliers to provide Wimax equipment, including Wimax-enabled phones, which are currently available in Europe and Asia, and in the United States by the end of the year. Sprint is upgrading its network with Wimax capabilities in a few markets; other carriers will soon follow suit.

Terrestrial and satellite broadcasters will feel the impact of this emerging technology within the next few years. In past articles, I have made a point that terrestrial broadcasters better start looking at their properties as platforms rather than a source of programming. They have a unique advantage of having coverage footprints that provide signals throughout most of the country. While IBOC might provide some audible parity with other digital mediums, broadcast operators need to begin to find ways of leveraging that coverage in ways that will adapt with future technologies.

McNamara is president of Applied Wireless, Cape Coral, FL.