Should LTE Gateways (SGW & PDN-GW) Co-locate and Merge?

Service Provider Mobility: Should LTEGateways (SGW and PDN-GW) Colocate andMerge?Posted by Ritesh Kumar Nov 7, 2009LTE Gateways - Serving Gateway (SGW) and Packet Data Network Gateway (PDN-GW)are used for LTE bearer path whereas Mobility Management Entity (MME) is used forsiganling. Lets look at hogh level functions for both the LTE gateways:• Serving GW: provides mobility anchor for inter eNodeB handover and paging trigger for downlink trafficawaits user. SGW is also used for 3GPP Inter-RAT traffic with S4 connectivity to SGSN. For PMIP basedversion, it would provide bearer session management and control.• PDN GW: provides connectivity from user to services. It provides network-wide mobility anchor, includingfor non-3GPP technologies. It provides bearer session management and control.With PMIP version almost on hold after Verizon made a decision to use GTP, ServingGateway's role as a separate entity provides very little function that PDN-GW does notperform, essentially data path mobility management events (paging trigger and eNodeBhandovers). Does this justify a separate entity in the data path with high throughput handling capabilites?An additional cost for operators? An additional question - does it need to colocate SGW?Should SGW and PDN-GW be hierarchical in nature? There are discussions on local offload at different hierarchical levels. With a mergedgateway, the local offload feature is same as SGi, reducing one more complexity. Reducinglatency on real-time applications including VoIP will be an easier discussion. Should 3GPP standard look at combining the two gateways? In my view, it should.What are your thoughts?Generated by Jive SBS on 2009-12-07-07:001Service Provider Mobility: Should LTE Gateways (SGW and PDN-GW) Colocate and Merge?195 Views Tags: distribution, lte, long_term_evolution, pdn_gateway, colocate, merge, sgw, lte_gateways,serving_gateway, pgwThere are no comments on this postGenerated by Jive SBS on 2009-12-07-07:002