 The input data considered for MMS services and which should be taken into account together with the general dimensioning sheet for PS traffic are given below. The most important input can be the total number of subscribers per year - usually given as the end-of-the-year number of subscribers. This input is combined with the relevant penetration values: GPRS penetration in the most likely case of MMS over GPRS; and MMS penetration, given as the proportion of GPRS terminals (GPRS penetration) that are MMS-capable. Others inputs are: Number of MMS messages per user per month: Other possibilities may have to be taken into account. Number of PDP contexts per subscriber per busy hour. Although not so relevant for the purpose of MMS dimensioning itself, the existing PS traffic could be included in the overall calculation. The average size of the MMS message: It is expected that it will grow in the future, when not only pictures and text, but also short audio and video clips come into use. Peak-hour multiplier: This is introduced to model busy traffic behaviour. Gb overhead and burstiness factors, Gn overhead factor: These are to be taken into account in the respective interface calculations. With these values, the result can be obtained in terms of number of MMS per subscriber per busy hour, which is the basis of the dimensioning exercise. MMS traffic just becomes some additional packet data traffic and the network needs to be dimensioned accordingly considering this new type of traffic. MMS NETWORK PLANNING Mobile-originated, mobile-terminated, application-originated or application-terminated MMS should be distinguished. For the GPRS bearer, and excluding the combination AO- AT, every event, either send or receive is a transaction, or a traffic happening, and SO has to be taken into account. For each mobile-originated or mobile-terminated message, one PDP context needs to be activated. Latest network element capacities should be checked and taken into consideration since it is possible to face different scenarios with