Mobile Solutions; Hsdpa Offload - Alcatel-Lucent 7705 Service Manual

Mobile Solutions

The Mobile Radio Access Network (RAN) is rapidly growing to meet the increased demand
in mobile services. This in turn increases demands on carriers to provide high-bandwidth,
mobile broadband services. Today, at a typical cell site, 2G and 3G base stations are
connected to high-cost, T1/E1 leased lines that are used to backhaul both voice and data
traffic to the MTSO. For mission-critical, delay-sensitive, and low-bandwidth traffic such as
voice, signaling, and synchronization traffic, it is vital that the high availability of these
leased lines is ensured. SLA agreements also promise a high level of availability for
customers.
Currently, however, best-effort traffic such as high-speed downlink packet access (HSDPA)
is also switched over these SLA-enabled leased lines. HSDPA is a 3G mobile telephony
communications service that allows UMTS networks to have higher data transfer speeds and
capacity, allowing the mobile customer (end user) to browse the Internet or to use the mobile
device. The increasing use of HSDPA is having a dramatic impact on the ability of the
T1/E1 leased lines to scale with the traffic growth as well as on the operating costs of these
lines.
Similar issues confront CDMA EVDO networks today.
Alcatel-Lucent provides a solution that enables mobile operators to keep their existing
infrastructure (circuit-based leased lines), while gradually migrating to a packet-based
infrastructure that will allow scalability, decrease costs, and ease the transition to the next-
generation, all-IP network solutions.

HSDPA Offload

The Alcatel-Lucent solution is to make use of widely available DSL networks and split the
traffic being backhauled. Mission-critical traffic (voice, signaling, synchronization) remains
on the T1/E1 leased line circuits, while the best-effort, bandwidth-hungry HSDPA traffic is
offloaded to DSL networks.
The 7705 SAR-F is an ideal candidate for this scenario. The 7705 SAR-F is a small-scale,
fixed version of the 7705 SAR product family. It is optimized for use in standalone small or
midsized sites where traffic aggregation from multiple cell sites is not needed. For more
information on the 7705 SAR-F, refer to the 7705 SAR-F Chassis Installation Guide.
7705 SAR OS Services Guide
Services Overview
Page 57