Alcatel-Lucent 7750 SR - ATM Backhaul for GSM;UMTS Network Infrastructure; Figure 21: ATM Backhaul for GSM;W-CDMA

Page 78 7750 SR OS Services Guide
ATM Backhaul for GSM/UMTS Network Infrastructure
Figure 21: ATM Backhaul for GSM/W-CDMA
As shown at the top of Figure 21, the most common deployment for GSM/W-CDMA mobile RAN
aggregation are leased E-1 facilities. 2G traffic is carried directly over these facilities and
connected to the Base Station Controller (BSC), typically on a channelized STM-n interface from
an SDH multiplexer. In addition, the Node B traffic is carried over E-1 ATM IMA facilities. These
are typically terminated on a channelized STM-n interface at the MTSO and aggregated onto a
concatenated STM-n ATM interface to the RNC. In this scenario, the 7750/7710-SR routers can be
the ATM IMA termination and aggregation platform.
With the continued rollout of High Speed Packet Access (HSPA) technology and the associated
increased bandwidth requirements, many mobile service providers are looking for a more cost
effective backhaul technology than E-1 PDH. Generally, Ethernet is considered the most cost
effective backhaul technology for n*2Mbps connectivity and has the ability to scale into gigabits
OSSG141
2G BTS
NodeB
Alcatel 5620 SAM
BSC,
MSC
BSC
ENET,
POS
ENET
ENET
TDM
Chan STM-n
ATM IMA
1) Centralized
L1 groomed to
MTSO IMA
termination.
No 2G TDM.
2) Distributed to Hub
Extend Ethernet transport
to hub site. Backhaul both
3G ATM PW and
2G TDM PW.
3) Fully Distributed
Extend Ethernet transport to cell site.
Backhaul both 3G and 2G.
77x0SR
77x0SR
MTSO
Hub
Cell
Site
TDM
Chan STM-n
ATM IMA
N x T1IMA
BTS
NodeB
BTS
NodeB
N x T1IMA
MLPPP
N x T1
TDM
N x T1IMA
MLPPP,
Ethernet
N x T1
TDM
ENET,
POS
TDM Grooming
(LEC)
TDM Grooming
(LEC)
Ethernet (MPLS)
Aggregation
Network
PDH MW/LL (L1)
or ENET
(MetroE, DSL, Cable,
Microwave
Eth
RNC