The Application Of Mobile Softswitch In GSM Network

Experts agree that today we are at the beginning of the third generation mobile communication system evolution, which has good capability to support multimedia communications and high rate data communications. However, the government has not decided when will be the right time to construct the 3^rd generation network. So the operators have to make a choice to use traditional MSC or to use Softswitch in core network. Out of question, using the common 2G/3G Softswitch will be the best choice.Mobile Softswitch has been introduced into WCDMA/TD-SCDMA core network since the 3GPP Release 4. The layered core network architecture is derived from the current standards reference model by separating the control plane functions in the MSC from their user plane functions, thus turning MSC node into MSC Server and Media Gateway. As a result, TDM can be replaced by IP, preparing future evolution towards an "all-IP" solution. In addition, it can optimize core network resources, provide low cost of O&M network and improve the QoS of speech and efficient band using. Mobile Softswitch plays the key role in the evolution from 2G to 3G.Adopting 3GPP R4 Softswitch during the expansion of GSM core network, it not only satisfies the need of current service, but also increases the skill of O&M. And we can prepare for the 3G O&M. When the 3G network developed, the 2G resources can be turned into 3G resources, allowing a very flexible re-use of investments in the GSM infrastructure.According to contract, all new MSC nodes must be substituted by MSC Server and MGW. I am very lucky to join the project of the ShanDong Mobile Softswitch technical solution. As one of the famous telecom equipment providers, Ericsson has a plenty of skills in the telecommunications, especially in domain of mobile communications. Based the feature of Ericsson' equipments and characteristic of ShanDong mobile GSM infrastructure, we made the mobile Softswitch technical solution. It can be divided into two steps. First, we add new MSC Server and MGW in JiNan city and QingDao city. At this step, the function of MSC Server and MGW are same as MSC. Second, based the first step, we can add more MSC Server and MGW. It is better to use the method of MSC Server in Pool. And also we can add new MSC Server and MGW in other cities. In addition, all MGWs work in one group in the same city.This article contains a comprehensive description of the connection method between Softswitch equipments and other GSM network nodes. After the finish of the project, however, the MSC Server and MGW just are used as GSM MSC. As a result, the advantages of using Softswitch do not appear from a statistical data point of view. With the development of the network, when the Softswitch techniques, such as MSC Server in Pool, MGW in group, TFO/TrFO and so on, are used, we will see the advantages of the softswich.Five chapters constitute the article. Chapter 1 deals with the description of GSM infrastructure and the significance of adopting Softswitch into GSM network. Chapter 2 is dedicated to the description of concept of Softswitch and NGN and protocols. Also the 3GPP R4 WCDMA core network infrastructure is introduced. Chapter 3 contains the description of Ericsson mobile Softswitch technique solution. In this chapter, the characteristics of Ericsson MSC Server and MGW are introduced, especially the feature of MSC Server in Pool and core network redundancy. The core network planning, including inter-province and intra-province, is also introduced. At the end of this chapter, the dimensioning of bearer band and signaling band is discussed. Chapter 4 deals with the description of change of ShanDong GSM infrastructure due to the adding of the MSC Server and MGW. At the last, the chapter takes the QingDao city as an example to introduce the topology of the core network. Chapter 5 makes a conclusion about the ShanDong mobile Softswitch solution and emphasizes the importance of introduce the Softswitch into GSM network today.