Comparison of Transport Capacity Requirements in 3GPP R99 and HSDPA IP-based Radio Access Networks

Growing number of subscribers and deployments of high speed air interfaces (e.g. HSDPA) are imposing stringent requirements for mobile backhaul. In this paper we perform a comparative study of the transport capacity requirements in an IP-based UTRAN when using either release´99 (i.e. DCH) or high speed channels (i.e. HSDPA) in the air interface. The analysis is focused in the interface between base stations and radio network controllers, referred to in the 3GPP as Iub interface. For both scenarios, the minimum bandwidth to be provisioned in the Iub interface is calculated for voice and data services, under different levels of traffic aggregation and delay requirements. Over such a basis, the influence of the protocol overhead within the bandwidth requirements is identified and a sensitivity analysis to factors such as the network size, traffic model parameters and channel rates is conducted.