Femtocell Management System; Femto Network Gateway; Femtocell Aaa Server; Ims Core Network Elements - Cisco ASR 5000 Series Administration Manual

Femto Network Gateway Overview
broadband connection (e.g., DSL or cable). A FAP allows operators to extend wireless service coverage indoors,
especially where access would otherwise be limited or unavailable.

Femtocell Management System

The Femtocell Management System (FMS) is a network element that resides in the operator's network and facilitates
the provisioning, activation, and operational management of the FAPs in the network based on industry standards such
as TR-069. The FMS helps to ensure the scalability of the FAP network to potentially millions of devices.

Femto Network Gateway

The Femto Network Gateway (FNG) is a network element that resides in the operator's network and functions as both a
security gateway and a femtocell gateway. The security gateway functions provide secure access for the FAPs to access
services within the operator's core network. The femtocell gateway functions provide aggregation and proxy capabilities
for the FAPs. The FNG forwards all voice traffic to the operator's IMS core network and all data traffic to the
PDSN/HA.

Femtocell AAA Server

The Femtocell AAA Server provides a FAP authorization function. It sends authorization policy information to the
FNG.

IMS Core Network Elements

An operator's IMS core network may include the following elements to enable voice services:
• P-CSCF: The P-CSCF (Proxy Call/Session Control Function) is the entry point into the IMS domain and serves
as the outbound proxy server for SIP messaging for the subscriber UEs. The UEs attach to the P-CSCF prior to
performing IMS registrations and initiating SIP sessions. All SIP signaling traffic to and from the FAPs and the
IMS core is handled by the P-CSCF. The P-CSCF provides message manipulation, breakout of emergency call
services, QoS (Quality of Service) authorization, and signaling compression. Once the P-CSCF completes all
of the functions for which it is responsible, it forwards the call to the I-CSCF.
• I-CSCF: The I-CSCF (Interrogating Call/Session Control Function) functions as a location server in the IMS
core network. Its major functions are to select the appropriate registrar server for the subscriber UEs by
consulting the HSS (Home Subscriber Server) and forwarding the request to the IMS registrar (the S-CSCF).
The HSS returns a set of required S-CSCF capabilities for initial registration requests by the UE. Based on
these capabilities, the I-CSCF selects the appropriate S-CSCF.
• S-CSCF: The S-CSCF (Serving Call/Session Control Function) provides session control and registration
services for the subscriber UEs and FAPs in the network. It is responsible for all aspects of session control,
handling all subscriber requests, which it relays to the appropriate application server. The S-CSCF routes
mobile-terminating traffic to the P-CSCF and routes mobile-originating traffic to the convergence server based
on iFC (initial Filter Criteria) downloaded from the HSS.
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Cisco ASR 5000 Series Femto Network Gateway Administration Guide ▄
Network Deployment(s) and Interfaces ▀
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