Wireless Broadband Technology

Wireless Broadband traditionally refers to ‘last-mile’ delivery of high speed data, typically for Internet access and private networking, in metropolitan and rural areas, over distances of hundreds of metres to several kilometres. WiMAX in particular has long been promoted as a viable alternative to DSL, including for triple play voice, video and data services. We critically examine the capabilities of this emerging technology in the context of limited spectrum availability in the frequencies best suited for longer distance propagation.

Another technology with great appeal for delivering broadband services without a cabled infrastructure is the use of Mesh Networking, with WiFi or WiMAX. One aspect of the Digital Dividend resulting from the digitisation of broadcast television is the decision by OfCom and the FCC to allow the utilisation of ‘White Space’– locally unused UHF TV channels for Wireless Regional Area Networks (WRANs). This will only be possible with a new generation of Cognitive Radio equipment, such as that being developed by IEEE Task Group 802.22. These WRANs may make use of Mesh Networking, and show considerable promise for providing broadband connectivity in rural and remote areas.

Mesh networking involves dozens or hundreds of nodes, sharing traffic between themselves, dynamically configuring themselves according to traffic patterns, propagation and interference limitations, to form a self-managing backbone network which can be spread, in principle, over large urban and perhaps rural areas. We report on the status of technical standards in this field and discuss the challenges which will need to be overcome in order to deploy robust, standards-based mesh networks.

While Bluetooth is neither long-distance nor broadband, it is a successful Personal Area Networking technology with several important implications. Firstly, it uses the same frequencies as most WiFi systems, requiring very careful coordination of frequencies and transmit/receive timing with any device, such as a laptop, which is both WiFi and Bluetooth compatible. Secondly, future broadband Bluetooth standards will enable the use the WiMedia UWB radio technology, greatly increasing its data rate and potentially improving its robustness.

WiMedia UWB is an advanced and promising technology now entering commercial production. Initially based on pulse techniques which covered vast ranges of frequencies, including those used for licensed services, UWB has emerged with a sophisticated OFDM radio specification which enables it, in principle, to avoid interference from and to other services, including WiMAX. We consider UWB’s promise as in in-building data- and video-centric networking system. We examine challenges such as the potential difficulties of implementing both WiMAX and UWB in the same device, or operating two such devices in close proximity.

Beyond UMB, an even more adventurous short-distance radio technology involves 5mm waves at 60GHz, with data rates measured in several gigabits per second, even from battery operated devices. We report on the four approaches to this technology: ECMA TC48, WirelessHD, IEEE 802.15.3c and 802.11 (VHT60).

We also report on current developments in Radio Frequency Identification, Near Field communications and WPANs, including Bluetooth, Bluetooth Low Energy (WiBree), 802.15.4 ZigBee, 6LowPAN, Z-Wave, ANT and En-Ocean.

Some of these technologies are being woven together to greatly enhance the communication capabilities of consumer devices. For instance, NFC is a sophisticated, highly secure, and very easy to use method of pairing Bluetooth devices in order that they can be used together. Bluetooth and its forthcoming Bluetooth Low Energy variant are suitable for a wide variety of applications – and Bluetooth is to be enhanced with WiMedia UWB for transferring gigabytes of data rapidly and with comparatively low power consumption.

The range of technologies discussed in this report spans very low data rate RFID to WiMAX, WiFi, UMB and 60GHz systems with bandwidths up to four gigabits per second. There are areas of overlap between the functionality of many of these technologies – and some conflicts between them due to their use of the same radio frequency spectrum without interoperability or thorough techniques of sharing the resource properly.