rvices via IP. DVB-S2 supports Adaptive Modulation and Coding (AMC) which allows the transmission parameters to be changed on a frame by frame basis depending on the propagation conditions for each individual user [10]. DVB-S2/RCS technology is especially useful for users where DSL or other broadband connections are either unavailable or satellite service is the preferred transmission technology. 7.3.7 Summary of Wireless Backhaul Technologies Table 7.2 summarizes the key parameters for each of the wireless backhaul solutions. It can be seen that there is not a single best technology that can address all the requirements of mobile backhaul. In Transmission Networks SUB-NETWORKS 2-WAY COMMUNICATION DVB-RCS HUB Internet DVB-RCS TERMINALS Figure 7.7 DVB-RCS network architecture. Reproduced from © 2009 DVB [11] addition, factors like redundancy, QoS, resiliency, and SO on, also need to be considered. The technology will be decided depending on the conditions on the ground. 7.3.8 Leased Lines Leased lines are today extensively used for cellular network backhaul because they can save a mobile operator from having to manage its own transmission infrastructure or be concerned with the underlying technologies and evolution. Most leased lines suffer from high cost due to the legacy time-division technology they are based upon and more often due to the monopoly of incumbent government owned landline operator. They also suffer from a lack of granularity of the bandwidth provided, which is typically offered in increments of E1 or T1. More leased line providers are positioning themselves to adopt Ethernet to reduce costs and provisioning time. This also reduces configuration overhead and increases the granularity of the bandwidth provided and quality of service management. Ethernet-based connectivity has started to become the de facto standard for all the current and future leased-line offerings [1]. 7.3.9 DSL Backhaul The flexibility of DSL (Digital Subscriber Line) and its wide availability make it an attractive backhauling 