| Introduction |
The explosive growth of the Internet over the last decade has led to an increasing demand for high-speed, ubiquitous Internet access. Broadband Wireless Access (BWA) is increasingly gaining popularity as an alternative “last mile” technology in this domain.Following the successful global deployment of the IEEE 802.11 Wireless Local Area Network standard known as “WiFi”, deployment of the IEEE 802.16-2004 standard (802.16d, generally known as Fixed WiMAX) Wireless Metropolitan Access Network (MAN) is now underway.
This technology aims to provide low-cost, high-performance broadband wireless access to residential and small business applications. Standardization was also completed recently for IEEE 802.16-2005 (802.16e, generally known as Mobile WiMAX), which will provide mobility to end users in a MAN environment.
As technology evolves to address portable and mobile applications, the required features and performance of the system will increase. Evolution toward the phase called “full mobility” provides incremental support for low latency, low packet loss and real-time handoff of subscriber terminals operating at high speeds. This requires enhancement to both the radio and network infrastructure. Mobile WiMAX technology is optimized to deliver high, bursty data rates to mobile subscribers, and the advanced Medium Access Control (MAC) architecture can simultaneously support real-time multimedia and isochronous applications such as Voice over IP (VoIP). Mobile WiMAX technology is uniquely positioned to extend broadband wireless beyond the limits of existing technologies. In this white paper, key considerations associated with deploying and operating mobile networks in different radio frequency bands.
Spectral considerations
The 802.16-2005 standard supports the frequency range of 2 to 6 GHz, although other frequency bands can also be accommodated. It is anticipated that additional frequency bands ona regional basis will also be auctioned. WiMAX operates in a mixture of licensed and unlicensed bands. The unlicensed bandsare typically the 2.4 GHz and 5.8 GHz bands. Licensed spectrum provides operators control over the usage of the band, allowing them to build a high-quality network. The unlicensed band, on the other hand, allows independents to provide backhaul services for hotspots. For the purposes of this white paper, 3.5 GHz and higher are defined as higher frequency bands. Currently, significant activity is underway in the 2.5 GHz and 3.5 GHz bands.
