Cisco 3825 - Manual (Page 13)

1-3
Cisco 3825 Mobile Wireless Edge Router Software Configuration Guide
OL-15667-03
Chapter 1 Overview of the Cisco 3825 Mobile Wireless Edge Router
Introduction
Another equally important benefit is that substantial excess capacity is now available in the existing
RAN backhaul network. The operator can reallocate this recovered bandwidth to carry traffic from other
radios, such as UMTS Node Bs, GPRS, EDGE, 1xEV-DO, PWLANs, and other data overlays. This
capability reduces the deployment and operating costs for new technologies, since the operator avoids
the up-front and recurring costs of supplementing backhaul capacity. It also accelerates time to revenue
from deployments of new radio technologies since there is no need for the operator to wait for additional
microwave licenses or leased lines to be supplied.
Compliance with 3GPP2 and 3GPP R5 and R6 transport standards is another appealing aspect of Cisco’s
RAN-O solution. Cisco converts today’s CDMA transport networks into 3GPP2-compliant IP RAN
transport networks, and GSM and R4/R99 UMTS transport networks into R5/R6 IP RAN transport
networks now—and adds multi-radio backhaul compression as well. This means operators can enjoy the
benefits of IP transport in their CDMA, GSM, and R4/R99 UMTS RANs today.
Figure 1-2 Example of Cisco 3825 Router in a GSM Abis and UMTS Iub Optimization over IP
Cisco GSM Abis Optimization over IP
The Cisco GSM Abis Optimization over IP technology improves T1/E1 bandwidth efficiency by 33% to
50%, corresponding to a GSM voice call capacity gain of 50-100% per T1/E1, depending on the nature
of the traffic on the interface.
In a GSM RAN, the interface between the BTS and BSC is a 3GPP reference interface called the Abis
interface. The physical trunk connecting a BTS and BSC is typically a T1 or E1 circuit, and carries 24
(T1) or 32 (E1) separate 64 kbps DS0 channels. One or two of these DS0 channels is used to carry control
and signaling traffic, while the remainder are used to carry bearer traffic—voice and data from mobile
PWLAN
WCDMA-TDD
WiMAX
(802.16/20)
GSM BTS
UMTS Node B
(R4/R99)
HSDPA
UMTS Node B
(RS/R6)
IP-PBX BSC
RNC
Cisco
Mobile
Exchange
100Base-T T1/E1
Cell Site Access Network BSC/RNC Site Mobile
Internet
Edge
Optimized Abis/lub over IP
Cisco
MWR
Mobile IP/FA
VoIP
Content Caching
Multi VPN
IP Multicasting
QoS
PPP
DHCP
Routing
ATM
IP
TDM
TDM
ATM
IP
Cisco
ONS 15454
IP-PBX
203232