Hi guys, hope this ain't off-topic too much.
I'm interested in how mobile communications networks use IP to transfer information in their core networks. I've been reading some books that describe the architecture of 3G and 4G systems, listing logical building blocks and their interfaces (things like eNodeB, MME, SGW, PGW...).
What I'm interested in is, what kind of actual devices make up these blocks? Obviously they are some kind of routers, switches, servers? If it's an IP network, what kind of layer 2 and layer 1 technologies do these interfaces use? What operating systems do they run? Can you point me to some books or websites that explain it in a more "real-world" way? Thanks!
I work in the mobile communications area--more on the Radio Access Network side--however, we all have to know networking these days!
To answer your questions:
A mobile network consists of a large number of cell sites anchored to a Mobile Switching Center (MSC).
The cell sites have:
eNodeB and/or BTS (Basestation Transceiver Subsystem) which contain the radio equipment needed to put the data over the air.
Router -- Cisco ASR1K or similar to interface the radio equipment to the IP network/ethernet connection back to the MSC.
At the MSC:
MME - Manages the interactions between the eNodeB's and SGW/PGW's. Handles mobility between 4G RAN's and can also assist with handoffs between eNodeB's.
The SGW/PGW's are specialized routers -- could be provided by Cisco, Siemens, etc: http://www.cisco.com/en/US/products/ps11079/index.html
Finally, all of the MSC's are linked via an IMS core. This is a huge topic but here is a sample of what the devices are like: http://www.cisco.com/en/US/prod/collateral/wireless/ps11035/ps11048/ps11081/data_sheet_c78-612146.html
There is a ton of stuff to learn and it looks like the new CCNP - SP certification will address some of these--for example use of IOS-XE.
Actual devices that make up a mobile network are supplied by different vendors. Those are for the core and access elements. (MSC,MSS,RNC,BSC,Enode-B,SGSN,etc.) But all of these nodes are now being routed via IP in case they need to communicate with each other. The infrastructure for IP Backbone/Core comes in which primarily in our case built with Cisco Devices(Platforms that are really scalable and can support large throughput). Layer 3 interfaces utilize the modules that are available. It can be electrical or via Fiber Optic. For greater bandwidth, 10G Xenpaks are also available. For Layer 2 and Layer 1 of these interfaces, they depend on the transport equipments (XDM 1000, etc).
You might want to read IP Design for Mobile Networks by Mark Grayson, Kevin Shatzkamer, Scott Wainner.