DS1/E1 TDM over Packet IP core

One of the main challenges in mobile backhaul networks is the transition from TDM to packet based infrastructure. TDM over Packet offers operators a smooth migration: TDM traffic from mobile base stations is packetized and transported on a unified packet backhaul network.

AimValley’s AC2050 TDM over Packet core simplifies the design of wireless backhaul systems and enables integration of all TDM and packet functions on a single Altera FPGA. With its support for 32 E1/DS1 framers and SAToP as well as CESoPSN mapping it enables ODMs and OEMs to reduce time-to-market and develop compact and cost effective equipment for the fast growing mobile backhaul market .

The new core is based on the successful and scalable TDMoP devices: AC2150 for the network edge, and AC2380 for aggregation applications. AimValley already shipped devices for several millions of TDMoP E1/DS1 lines.
“Our TDMoP solutions provide critical features such as DCR, ACR or retiming independent per channel”, says Jan Venema, CTO of AimValley. “With our expertise in synchronization and clock recovery we enable our customers to build Carrier Ethernet backhaul products with excellent jitter and wander performance.”

The AC2050 is available as an Intellectual Property (IP) core, fully compliant with Altera’s Qsys system integration tool. Qsys allows designers to easily connect, simulate and test IP cores in an FPGA. A complete Mobile Backhaul system can be built by adding other functions from the Qsys library to the AC2050 core and rapidly prototype and test on an evaluation board.

AimValley can provide a dedicated evaluation system to help developers rapidly build and test a specific system configuration. Software drivers and the interactive online scripting environment enable plug-and-play configuration and prototyping for fast time-to-market.

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Product overview:

High Level Features

• TDM over Packet IP core for 32xDS1/E1
• Plug-and-play evaluation in Altera Qsys
• CESoPSN and SAToP modes
• Wander compliant to MEF18 and G.8261
• Integrated E1/DS1 framer; DDR2 buffer
• Applications:

• TDM over Packet
• Wireless backhaul systems
• Wireline network migration

Overview

The AC2050 TDM over Packet IP core implements Circuit Emulation Services Interworking Functions (CES IWF) for 32 DS1/E1 TDM channels.

The AC2050 is available as an IP core, fully compliant with Altera® Qsys. The Qsys system integration tool saves significant time and effort in the FPGA design process by automatically generating interconnect logic to connect intellectual property (IP) functions and subsystems.

Evaluation of the AC2050 core is easily accomplished via the intuitive plug-and-play environment. An FPGA with on-chip CPU, Ethernet packet interfaces and the TDMoP core can be quickly built and simulated, and then tested on an eval board.

A complete wireless backhaul system can be created on a single FPGA by adding other functions from the Qsys IP core library. All interfaces to the TDMoP core are Qsys compliant to enable easy integration.

The AC2050 implements the SAToP and CESoPSN modes defined by IETF, MEF, MFA and ITU. These support transport of transparent DS1/E1 channels, or provide bandwidth efficient nx64 fractional channels.

The integrated DS1/E1 framers enable fault and performance monitoring, including test pattern insertion and loopback. The IP core supports Ethernet, VLAN, IP and MPLS PWE3 packet headers.

Each TDM channel can be configured independently for adaptive, differential or retiming clock recovery mode, and each channel may operate at a different clock rate.

The core is ideally prepared for new protocols or standards evolution due to its FPGA based design.

Evaluation systems are available for system level testing.

Features

• TDM over Packet CES IWF for 32 DS1/E1 ports
• SAToP or CESoPSN transport mode selectable per channel (RFC4553 and RFC5086)
• Configurable amount of TDM data per packet
• Clock recovery mode selectable per channel: adaptive, differential or retiming mode
• RTP header for differential clock (RFC3550)
• Jitter and wander compliant to MEF18, ITU-T G.8261 and G.823 / G.824 for traffic interfaces
• Configurable jitter buffer size
• Extensive set of CES fault and performance monitoring points
• Integrated DS1/E1 framer with alarm, fault and performance monitoring, and support for loopbacks and PRBS maintenance functionality
• Integrated packet header processor for MAC addresses, VLAN tags, IP and MPLS PWE3 headers

Interfaces

• TDM interface to LIU at 1.544 or 2.048 Mb/s
• Qsys Avalon Streaming packet interface
• Qsys Avalon MM CPU interface
• DDR2 DRAM for jitter buffer
• FPGA target: Cyclone® IV or V

Typical system applications for the AC2050 include:

• TDMoP CPE and provider edge equipment
• RBS or BTS base station network cards
• Carrier Ethernet Switch or router blade for TDMoP network aggregation
• TDM business access equipment for leased line migration
• CMTS cable head-end
• AMC I/O cards for ATCA and MicroTCA

A companion device, the AC2380 – OC12/STM4 TDMoP Gateway, targets TDM over Packet aggregation applications. These applications may use mid-end or high-end Altera devices such as Arria® or Stratix® depending on the level of integration. The AC2050 IP core and AC2380 are based on the same processing core and allow for seamless end-to-end interworking.