Most deployed wireless base stations connect to the backhaul network via PDH circuits (typically, T1s or E1s). These PDH circuits may be used to backhaul traffic directly from the cell tower to the mobile switching center or connect into microwave radios at the cell tower for backhaul to hub site locations, which aggregate the traffic over a SONET or SDH optical transport network back to the mobile switching center.

Each cell site typically supports several generations of wireless base station technologies. As new generations are deployed, the existing technologies must still be supported. Mobile operators also must support the growing data traffic as they ensure that subscribers' quality of experience for voice calls is not compromised.

As mobile operators upgrade their base stations to support Ethernet interfaces (UNIs), they must also transport that Ethernet traffic over existing PDH backhaul networks or PDH connections to microwave radios to connect to the backhaul network. Unfortunately, because of PDH circuit contractual commitments with PDH access network providers, fiber to the cell tower availability and the depreciation of microwave radio capital equipment, many mobile operators cannot upgrade their backhaul networks to natively support carrier Ethernet over fiber. Therefore, mobile operators must use their existing PDH-based infrastructure more efficiently to support their legacy, circuit-based services while they introduce and expand their packet-based mobile broadband data services. Mobile operators would prefer fiber to the cell site if it can be deployed cost effectively. However, most cell sites will not have access to a fiber backhaul network in the foreseeable future.

High-speed 3G data services, such as high-speed packet access (HSDPA and HSUPA) services, enable ubiquitous mobile broadband data connectivity. However, mobile operators face a number of technical, operational, and business challenges to reduce recurring OpEx for their PDH-based backhaul network connections.

How can mobile operators more efficiently use their existing PDH-based wireless backhaul network to support legacy 2G (TDM circuit-based) services as they introduce new, rapidly growing 3G (ATM-based) services, which will eventually evolve to 4G (all IP-based) services?

How can mobile operators tightly manage their PDH circuit OpEx to maintain margins as they ensure high quality voice with an explosive increase in data traffic?

How can mobile operators leverage their existing capital assets in PDH infrastructure and PDH-fed microwave radios as they minimize the total cost of ownership (TCO) with a flexible solution that evolves as their service portfolio changes?

Turin's iConnect™ for Wireless Backhaul solution utilizes the MASTERseries® smart integrated access device (SIAD) for A-bis optimization and the Traverse® multiservice transport switch for Ethernet, packet-based optimization over PDH circuit-based wireless backhaul networks.

The MASTERseries SIAD performs cell site base station traffic aggregation traffic management and A-bis bandwidth optimization for transport over PDH or Ethernet backhaul network connections to the cell site.

The Traverse platform provides high-density traffic aggregation grooming and switching of TDM and Ethernet over PDH traffic at the mobile switching center and at hub sites in a SONET/SDH or carrier Ethernet transport network.

The TransNav Element Management System is an advanced management system designed to support comprehensive control, fault, configuration, accounting, performance, and security monitoring. Through a feature-rich graphical user interface, operational and support personnel can control, configure, and trouble shoot their network of Turin products.

Most 2G and 3G base stations today connect to the network via T1 or E1 PDH circuits. The A-bis interface transports signaling protocols and compressed voice data between the base station (BTS) and base station controller (BSC) in a GSM network. An effective method to reduce the number of T1 or E1 PDH circuits required between the BSC and MSC is through A-bis optimization.

The Turin MASTERseries platform provides lossless A-bis optimization by utilizing silence periods and eliminating redundant data in the traffic stream during idle periods. This bandwidth optimization reduces backhaul bandwidth requirements from forty to fifty percent, enabling mobile operators to add subscribers or services over the existing T1 or E1 PDH circuits and defer adding T1 or E1 PDH circuits.

Because the MASTERseries A-bis optimization solution is lossless, it reconstructs the original traffic patterns precisely, resulting in identical voice quality as measured via the MOS (Mean Opinion Score).

The Turin Traverse platform's Ethernet over PDH (EoPDH) capability enables Ethernet-attached base stations to efficiently connect over the existing copper PDH (T1/T3, E1/E3) backhaul network or PDH-equipped microwave radios at the cell site.

With the same attributes for Carrier Ethernet delivered over fiber (EoF), EoPDH enables mobile operators to evolve their 3G base stations to Ethernet and add new 4G base stations as they continue using existing PDH backhaul infrastructures or PDH-based microwave radios. EoPDH bonds multiple PDH circuits together and capitalizes on the statistical nature of packet-based Ethernet traffic to send data traffic when voice traffic is not transmitted. Voice, data, and base station control traffic also get appropriate QoS to ensure that the time-critical voice and control traffic have emission priority over the best effort data traffic.

With the Turin Traverse platform, service providers have a highly scalable EoPDH aggregation solution that also provides a scalable digital cross connect system (DCS) that grooms and cross connects the legacy TDM traffic from 2G base stations.