It is important to notice that 3GPP standards define an MMS server for storing and handling and a MMS relay is responsible of the transfer of messages between different Mobile Station B: Receiver Mobile Station A: Sender 3. WAP GET 1 WAP POST Packet Core Network 2. WAP PUSH OVER SMS MMS CENTER WAP GW MMS RELAY MMS SERVER Figure B.2 General overview of MMS system architecture MMS NETWORK PLANNING messaging systems. On the other hand, the WAP-Forum organisation defines an MMS server and MMS proxy-relay. In most cases these two functions (MMS server and MMS relay) are combined and we commonly call the unit an MMS server or MMS centre. B.3 MMS NETWORK PLANNING MMS Network Dimensioning The input requirements for proper dimensioning of an MMS-capable GPRS network are described below. Figure B.3 shows a general flow for MMS dimensioning and planning. Traffic Input Traffic-related input is probably the most important from a planning point of view. It can be categorised according to different criteria. The following sections provide a deeper understanding of the different types of traffic input that can be given. Current GPRS Network Assessment It is crucial to understand the existing GPRS infrastructure, since MMS will be deployed over existing GPRS networks in most cases. This assessment must be done from several points of view with the existing traffic load and configuration, and in particular: SGSNs: number, HW and SW version, capacity equipped, interfaces types and capacity GGSNs: number, HW and SW version, capacity equipped, interfaces types and capacity DNS: firewall, WAP gateway and router configuration and capacities core sites: geographical location, backbone connectivity, centralisation/distribution of servers and other equipment types of service offered: Internet access, corporate intranet access, e-mail, WAP current level of usage of those packet services, including traffic load for the GSNs and the backbone. The output of this assessment can be a report containing a description of the above items as well as 