s should be a simple matter of dividing the total amount of subscribers expected to be served by the core site under review in a given year by the maximum attached subscribers capacity of an SGSN node, rounded up to the next integer number. The same approach as taken previously applies in this context. In this case, the point is to evaluate whether all the subscribers under any given SGSN of the core site under review, as defined by the Iu-PS homing and connectivity plan previously considered, can be served. This should be correct under the assumption that all the subscribers generate traffic uniformly, but on some occasions there might be different subscriber categories given as input t-residential versus business users - that may generate different types of traffic in different areas. Therefore, this aspect should be checked in those cases. Finally, the last calculation will be based upon the maximum number of simultaneous PDP contexts. Similar to the previous situations, the point is firstly to have a rough estimate of the maximum amount of SGSN nodes. The procedure consists of dividing the total amount of simultaneous PDP contexts expected inside the coverage area of the core site under review by the maximum amount of simultaneous PDP contexts per SGSN node, rounding up to the nearest integer. As in the previous step, in the case where all the subscribers uniformly generate PDP contexts (for instance, one PDP context per user during the busy hour), the calculation should suffice. However, in the case of having different types of subscribers with different amounts of PDP context generated by different types of subscribers, the same check as in the previous step should be carried out, to ensure that all the PDP context under a given SGSN coverage area can be served by the SGSN. It should be noted that with the introduction of new types of services and mobile phones with a multiple PDP context capability, this aspect may gain importance, although for the current situation this limiting factor is seldom the most 