 urban High Speed/Rural Note: Case 1 is shown in Table 3.13. Sources: C 2009 3GPP [4], C 2008 ITU-R [5], C 2009 IEEE [6] Recap and Future Outlook Service Service Platform Platform MSC/SGSN MSC/SGSN BSC/RNC BSC/RNC BTS/NodeB BTS/NodeB Figure 13.2 Site sharing. Reproduced with permission from C 2008 Frisanco et al. [7] Some infrastructure sharing options between operators are as follows [7]: Radio Site Sharing: This is the most basic passive infrastructure scenario where a third party owns the radio sites and any operator can place its radio and transmission equipment at that location. This concept as shown in Figure 13.2 has been popular is some countries and also has been made mandatory by some regulators. Regulators encourage site sharing, because it means that in total a fewer number of sites will be needed, which is desirable, considering environmental and esthetic concerns for the population. Active RAN Sharing: There are two approaches to this method of network sharing - one that involves frequency sharing (MOCN) and one without it (MORAN). MORAN Multi Operator RAN), a termed coined by NSN is a technical solution where operators share active RAN infrastructure (i.e. BTS and BSC in 2G or Node B and RNC in 3G networks). It is a technical solution as shown in Figure 13.3 where operators maintain a maximum level of Next Generation Mobile Communications Ecosystem Service Service Platform Platform MSC/SGSN MSC/SGSN BSC/RNC With Dedicated BTS/NodeB Frequencies Figure 13.3 MORAN based sharing. Reproduced with permission from C 2008 Frisanco et al. [7] independent control over their traffic quality and capacity, for example, each operator maintains its own set of cell-level parameters, only site-level parameters are shared. MOCN: MOCN (Multi Operator Core Network) is a 3GPP Release 9 feature [23.251] originally defined in Release 6.MOCN adds frequency sharing (Figure 13.4) on top of MORAN which results in some marginal savings. MOCN might not be feasible in some countries due to regulatory constraints. In April 2009,