Overview

Definitions for wireless broadband are as ubiquitous as definitions for broadband technologies themselves. Generally, wireless broadband technologies can be described as technologies to enable data transmission over radio spectrum. Wireless broadband technologies can perform on either a small coverage or on a larger coverage scale. Thereby, wireless broadband technologies use many frequency bands. As a matter of fact, the term, “wireless broadband” is often used to describe a cluster of various technologies which are themselves based on various technological standards for transmitting radio signals.

The most common wireless technologies can be clustered in two categories: WiMAX and Wi-Fi Technologies:

WiMAX Technologies: WiMAX (Worldwide Interoperability for Microwave Access) is the name for a cluster of wireless technologies that emerged from the IEEE 802.16 [vii] WirelessMAN (Wireless Metropolitan Area Network) family of standards. WiMAX Technologies occur either as (locally) fixed solutions or mobile solutions.
 

As fixed solutions, WIMAX technologies are often designed to serve as a wireless DSL replacement technology, to compete with the incumbent DSL or broadband cable providers or to provide basic voice and broadband access in underserved areas where no other access technology exists.  In this case, wide area wireless system uses a network of fixed antennas to offer high-speed broadband access over the air, rather than through a phone line or cable. WiMax technologies are suited for wide area coverage, such as proving broadband Internet access to a whole city.
 

WiFi (Wireless Fidelity) technologies are usually suited for single connections or small coverage, although they work on the same transmission standard principles. [viii] WiFi is traditionally a home and enterprise networking technology and is being used for broadband access in public areas such as airports, hotels, sports arenas, convention centres, and coffee shops. It is typically used to set up private wireless networks in a home or office, allowing you to move your PC or laptop while still having access to the Internet and to your printer and other devices This allows users to take their laptop and PDA devices with them and to use a common access technology to deliver high-speed Internet services in their office, home, and while on the road. Publicly accessible Wi-Fi spots are already widely available, especially in highly desirable locations such as hotels, airports and college campuses. Wi-Fi hot spots are also increasingly available for free to consumers as a service differentiator from restaurants and coffee shops and as a free public service from local municipalities.

As an alternative to wired networks, Bluetooth exist as a wireless standard. Bluetooth was developed to replace the need for interconnect cabling between devices for short-range and relatively lower data rates.
 

Advantages and Limitations

What are the capabilities and advantages of using wireless broadband technologies?

Wireless Broadband Technologies can offer a variety of advantages over wired broadband access:

• Performance: Wireless broadband modems can offer similar performance to cable modems operating over wired cable television systems (CATV), but the business is easier to enter as the transmitters cover an entire city or region. A broadband wireless system can deliver up to 30-Mbps data capacity in a 6-MHz channel. The wireless system's strength is that it can quickly provide high burst speed Internet access to a 10-mile, 20-mile, or 35-mile radius depending on the frequency band used. This allows the service provider to work with or compete to serve small-sized and medium-sized business and high-end users. The CATV coaxial-cable plant typically services residential neighbourhoods and may not be available to serve business customers located in business districts and industrial parks. Thus, wireless broadband platforms are an increasingly popular alternative for business and residential consumers.
  
• Connecting Rural Areas: Wireless networks are increasingly becoming the only solution for getting broadband connectivity into some rural and semi rural areas.  In several regions of the world, copper wire to the home or business just doesn't exist. In these situations, a fixed wireless offering that is based upon an open standard may make more economic sense than deploying copper wire that can easily be ripped out and resold on the open market. The overall use of WIMAX in rural areas has been relatively small so far, which relates to the overall market failure in providing broadband access to rural areas.
  
• Enhance WiFi Networks: Additionally, WiMAX can potentially be used to provide backhaul in cellular networks or it can be used to significantly enhance the performance of public Wi-Fi (Wireless Fidelity) hot spots by increasing the throughput in the backhaul network and by making it easier and more economical to deploy Wi-Fi access points.
  
• Costs “Off the Shelf Technology”: WIFI and WiMAX technologies have the capability of becoming a credible solution to a number of problems that have related to market failure and role out of fixed line broadband access. Particularly WiMAX certified equipment is becoming increasingly available from a number of suppliers, due to increased competition, raising demand and economies of scale that lead to the fact that more attractive prices for the necessary technology is being reached. WIMAX Technologies are available “off the shelf” which allows, for instance, to build small community networks for relatively low costs. According to the World Bank African Backbone Study, the reduced costs of local redistribution can help to offset the higher costs of adding additional connection points along the cable. Microwave and mobile towers or masts already provide easy access to local communities along trunk routes while fibre-only routes require more costly add-drop units to reach some local communities. Thus deploying WIMAX connection at least in certain geographically suitable areas may be a cost effective alternative of providing broadband access.

What are the constraints and disadvantages of using wireless broadband technologies?

• Interference in the Radio Spectrum: Wireless standards – especially for WIFI Technologies - must address potential transmission interference with other devices, including microwaves, cordless telephones, and other wireless standards that operate at the same frequency.
• Congested Networks/Sharing Bandwidth: Since WiFi shares the airwaves with devices such as microwaves and cordless phones and any potentially unlimited number of users in the coverage area, this may pose limitations on bandwidth availability. This may become less of a problem with new WiFi technologies.
• Security Concerns: Since the connection to a single computer or a network of computers is provided by using the radio spectrum, rather than by using a single physical and proprietary connection, it can be fairly easy for other users to “tab” into the network. This raises security issues with regards to the open airwaves of the wireless networks, and how users and administrators will deal with spam, viruses, filters and the usage of encryption techniques.
• Line of Sight: Some, especially older wireless technologies, may require line-of-sight between the transmitting and receiving points. This can be a problem in some areas.

Wireless Technology and Local Open Access Networks

Wireless technology is being used for Local Open Access Networks in a number of locations throughout the world with most of the deployments being done by local Governments or voluntary groups.  The major advantage that wireless has over other technologies is that it is relatively inexpensive and can be deployed quickly. Some examples include AllCoNet [ix] deployed by local government and not for profit entities in Allegany County, Maryland and the volunteer operated Djurslands.net[x] providing wireless broadband services to the Djurslands region of Denmark.

 
LOANs using a wireless technology platform may be one of the more cost effective solutions for the delivery of high-speed Internet services to underserved groups in both developed and emerging economies.  In some instances, wireless access technologies could be used as a transitional technology prior to the full deployment of an FTTH system. It allows for the provision of some basic services in relatively immature markets and captures customers who can then be migrated over time to support more enriched bandwidth hungry services.