This post talks about LTE architecture
Following are the main nodes in LTE:
1.UE :- User Equipment
UE is the device user uses to access the lte network. Can be a datacard or a mobile which is LTE capable.The device will access the services provided by the lte network. (see http://www.ltesimplified.blogspot.com/2012/02/babysteps-to-lte.html to know the common services provided)
LTE e-UTRAN
2.eNodeb :-
When our LTE UE communicates to the LTE network, first point of contact is eNodeb. If you are familiar with other wireless technologies,eNodeb is a combination of BTS/NodeB+ BSC/RNC. It owns the entire radio resources(frequencies) within its designated area and allocates them to mobiles. UE connects to eNodeb through a LTE-Uu Interface
LTE Core Network (Also called SAE-System Architecture Evolution)
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3.Mobility Management Entity (MME):
MME is the key control node of LTE core network.Major functions done by the MME are registration,mobility,paging,authentication. S1-MME interface connects MME to eNodeb. As shown in the architecture diagram, MME inerfaces with S-GW(S8/S11) , HSS (S6a) and even with other technology nodes like SGSN
4.Serving Gateway:
S-GW is in the user plane of LTE CN . It routes and forwards user data packets, It is the mobility anchor for the user plane during inter-eNodeB handovers and as the anchor for mobility between LTE and other 3GPP technologies. S-GW interfaces with P-GW through S5 interface.It may interface with SGSN also for handover support.
5.PGW (PDN Gateway):
The PDN Gateway provides connectivity from the UE to external packet data networks It can be considered as the point of exit and entry of traffic for the UE. It is the mobility anchor during handover between LTE and non3GPP technologies
6.HSS (Home Subscriber Server):
The HSS is a central database that contains user-related and subscription-related information.Similar to HLR +AuC in the older architectures
7.PCRF: Policy and Charging Rules Function
PCRF is the node designated to determine policy rules and charging rules .Its functions are administrary in nature mainly.
A simple architecture diagram for LTE network is available at the below link (wikipedia)
http://en.wikipedia.org/wiki/File:LTE_System_Architecture.jpg
A simple architecture diagram for LTE network is available at the below link (wikipedia)
http://en.wikipedia.org/wiki/File:LTE_System_Architecture.jpg
