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1. Service Provider Mobility: Should LTE
Gateways (SGW and PDN-GW) Colocate and
Merge?
Posted by Ritesh Kumar Nov 7, 2009
LTE Gateways - Serving Gateway (SGW) and Packet Data Network Gateway (PDN-GW)
are used for LTE bearer path whereas Mobility Management Entity (MME) is used for
siganling.
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 traffic
awaits user. SGW is also used for 3GPP Inter-RAT traffic with S4 connectivity to SGSN. For PMIP based
version, it would provide bearer session management and control.
• PDN GW: provides connectivity from user to services. It provides network-wide mobility anchor, including
for non-3GPP technologies. It provides bearer session management and control.
With PMIP version almost on hold after Verizon made a decision to use GTP, Serving
Gateway's role as a separate entity provides very little function that PDN-GW does not
perform, essentially data path mobility management events (paging trigger and eNodeB
handovers).
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 merged
gateway, the local offload feature is same as SGi, reducing one more complexity. Reducing
latency 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 2009-12-07-07:00
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2. Service 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, pgw
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Generated by Jive SBS on 2009-12-07-07:00
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