System Infrastructure Of Base Station Interconnection Based On Abis-over-IP And Research Of Clock Recovery Algorithm

Today telecommunication technology has developed faster than ever, especially within the last three years, as we all see it, the 3G is on its way to boom. However, GSM network still leaves some places uncovered yet.Among all the barriers, the cost of setting up long distant wired communication connection is the key to the issue. Fortunately, since some significant progresses of broadband satellite access technique, transporting the traffic on GSM trunk lines via satellite tunnels turns into possible. Migrating Abis traffic onto IP-base satellite links could easily spread out the coverage area to the wildest regions which only satellite signals are available. Without redesign the Base Station equipments, like BTSs and BSCs, this new technique named Abis over IP for Base Station Interconnection could easily turn the possibility into reality.In this dissertation, the system architecture of GSM has been introduced firstly, and the data format on Abis interface is discussed in detail. Then principles of Abis over IP Gateway are well explained, including hardware configuration, module division and procedure of data flow. There is a general description to the gateway infrastructure, followed by module inside specifications which contain all the five major modules. After that, the algorithm of Synchronization and Clock Recovery is analyzed detailedly. Furthermore, validation to the algorithm has been attached.