E 802.20-2008 (2008) IEEE Standard for Local and Metropolitan Area Networks - Part 20: Air Interface for Mobile Broadband Wireless Access Systems Supporting Vehicular Mobility - Physical and Media Access Control Layer Specification, IEEE, June. 5. Greenspan, A., et al. (2008) IEEE 802.20: Mobile broadband wireless access for the twenty-first century. IEEE Communications Magazine, 46 (7), 56-63. 6. Bakmaz, B.M., et al. (2007) Mobile Broadband Networking Based on IEEE 802.20 Standard. 8th International Conference on Telecommunications in Modern Satellite, Cable and Broadcasting Services, September 26-28, 2007, Nis, Serbia, pp. 243-246. 7. Jalili, A., et al. (2009) Effects of Different Mobile Channel Conditions on IEEE 802.20. 2009 International Conference on Computer Engineering and Technology, January 22-27, 2009, Singapore, pp. 287-291. 8. Jalili, A., Fakhraie, S.M., and Esfahani, S.N. (2009) Performance evaluation of IEEE 802.20 PHY Layer. 2009 International Conference on Computer Engineering and Technology, January 22-27, 2009, Singapore, pp. 161-165. 9. Oguma, H., et al. (2009) Comparison of Downlink Throughput Distributions between Frequency Reuse Factors of One and Three in MBWA System Field Trial. 4th International Symposium on Wireless and Pervasive Computing 2009, February 11-13, 2009, Melbourne, Australia, pp. 1-5. Transmission Networks 7.1 Introduction In a cellular network, the traffic from Cell Sites to the BSCs/RNCs and further to the Mobile Switching Centers and Data Gateways and finally to the outside world is carried by what is known as Transport Network or Transmission Network. In a nutshell, the purpose of the transmission network is to provide reliable aggregation and delivery infrastructure for the transport of any type of traffic. From a network hierarchy perspective as shown in Figure 7.1, the transport network can be divided into three segments: access (backhaul) network, metro or regional network and core (backbone) network. This segmentation is not a standard and could change from operato