Alcatel-Lucent 7750 SR Manual page 71

Migration Strategies
Suggested migration strategies for the mobile solution technologies include:
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CDMA — UMTS
CDMA2000 starts with new channel cards and migrates to a full mobile IP infrastructure requiring
new Core Network (CN) infrastructure such as the AAA server and Packet Data Server Node
(PDSN).
To support CDMA2000 (1xRTT) Radio Access Network (RAN) to the interface with a GSM Core
Network impacts the RAN which would require an upgrade of the CDMA base station and BSC.
A core network upgrade requirement includes a CDMA PDSN and AAA server.
Some functionality of the serving gateway may be integrated into the MSC MLS or router. The
SGW routes and forwards user data packets, while also acting as the mobility anchor for the user
plane during inter-eNodeB handovers and as the anchor for mobility between LTE and other 3GPP
technologies (terminating interfaces and relaying the traffic between 2G/3G systems and PDN
gateway).
eNode-B or eNodeB (eNB) interfaces with the UE. The eNB hosts the PHYsical (PHY), Medium
Access Control (MAC), Radio Link Control (RLC), and Packet Data Control Protocol (PDCP)
layers that include the functionality of user-plane header-compression and encryption. It also
offers Radio Resource Control (RRC) functionality corresponding to the control plane. It performs
many functions including radio resource management, admission control, scheduling,
enforcement of negotiated UL QoS.
GSM — UMTS
When converting a GSM network to a UMTS network, the first new technology is General Packet
Radio Service (GPRS). It is the trigger for 3G services.
From GPRS, operators may change the network directly to UMTS, or invest in an EDGE system.
One advantage of EDGE over UMTS is that it requires no new licenses. The frequencies are also
re-used and no new antennas are needed.
W-CDMA uses the same core network as GPRS, utilizing existing infrastructure such as the
GGSN and SGSN. W-CDMA, however, requires new RAN infrastructure such as the Node B,
which replaces the BTS, and the Radio Network Controller (RNC), which replaces the BSC.
7750 SR OS Services Guide
CDMA — UMTS on page 71
GSM — UMTS on page 71
Services
Page 71