echniques increases this and adding channels multiplies the capacity. 3 http://www.ericsson.com/ericsson/corpinfo/publications/review/2009_02/files/Backhaul.pdf Wireless Core Network Hardware As at 2011 Ericsson are/were offering 14 MHz or 28 MHz channels for LTE backhaul with the longer-term option of migrating to aggregated 28 MHz channels. The lightly licensed 71-76 GHz and 81 to 86 GHz bands known as E band support 10 GHz bandwidths but using simpler modulation on a single carrier. The light licensing has been adopted in the US and UK, takes a few minutes online and costs about $100 dollars a year. The bands became available in the US in 2003 and in 2006 in Europe. Using these bands, however, depends on local weather conditions. A tropical rainstorm every afternoon will seriously affect availability and throughput, but then we don't get a lot of tropical rainstorms in the UK, though actually we had one yesterday. There are some applications where throughput becomes more important when it rains. For instance, there are generally more traffic accidents and cars tend to break down SO calls to the emergency and breakdown services will increase. Snow storms can also be a problem at some frequencies as can sand storms, though we don't get a lot of those in the UK either. For all of these weather-related events availability can be provided in other ways, for example by having multiple routing options or by having other microwave links at other frequencies. The copper offer (reviewed way back in Chapter 2) includes high bit rate DSL (HDSL), enhanced high bit rate DSL (HDSL2) and in some cases single pair HDSL (SHDSL). If there is a fibre to the curb nearby then this allows enhanced very high speed DSL (VDSL2) to be used providing 100 Mbps of upstream and downstream bandwidth. The 100 Mbps can be increased by implementing a crosstalk cancellation technique called vectoring and line bonding (multiple twisted pairs dedicated to the link). The vector cancellation characterises the crosstalk from the adjacent VDSL twisted