Symmetricom’s TimeProvider® 2700 Edge Grandmaster Clock and TimeProvider® 2300 Edge Boundary Clock are a new type of IEEE 1588 Precision Time Protocol (PTP) equipment designed for deployment in the mobile backhaul network, at macro base station sites, or small cell aggregation locations. These Edge Master Clocks are optimized to enable economic deployment of small cells and meet the stringent timing and synchronization requirements of 4G/LTE networks following the approach anticipated in the proposed ITU-T G.8275.2 standard for partial on-path support.
Edge Master Clocks
The continuing evolution of mobile network technologies has driven the need for increased accuracy and greater availability of timing and synchronization signals. At the same time, backhaul networks with high packet delay variation present timing “jitter variation” and asymmetry challenges that are difficult to solve with current solutions. Retrofit of backhaul networks for full on-path support is often not economically feasible, while deploying a GNSS receiver at every base station location is impractical, particularly in many small cell environments. Together, these issues create the need for a new synchronization distribution architecture for LTE networks.
Edge Master Clocks are PTP synchronization solutions designed for deployment in current networks by locating a grandmaster at or near the edge or by overlaying the network with advanced boundary clocks at planned locations. They enable mobile network transitions to include small cells, and they support the stringent LTE-TDD and LTE-A phase and time requirements without overhauling the current backhaul network. In frequency synchronized networks (LTE-FDD, as well as 2G/3G), Edge Master equipment can be deployed to eliminate timing issues caused by diverse technologies in the backhaul network, high packet delay environments, and asymmetry inherent in Carrier Ethernet networks.
Together, Symmetricom’s Edge Master products enable synchronization distribution solutions that allow the mobile network to continue to evolve without retrofit of existing backhaul equipment and without changes to current network design and switching/routing policies.
TimeProvider 2700 Edge Grandmaster Clock
The TimeProvider 2700 PTP Grandmaster standard capabilities include either a GPS or GLONASS input, allowing it to fulfill the requirements as a Primary Reference Time Clock as defined by the ITU-T G.8272 standard for phase and time synchronization, as well as G.811 for frequency reference. The TimeProvider 2700 provides two gigabit Ethernet interfaces in a combo port configuration supporting use of either copper or optical connections. Synchronous Ethernet is supported on the input and output ports. Models are available to support 8, 16, 32 or 64 PTP clients; all operating at the full 128 messages per second rate. Client capacity can be increased in the field with software license options. The TimeProvider 2700 is available with either an OCXO or rubidium oscillator; each delivering a different level of phase and frequency holdover performance and allowing operators to better optimize their network SLAs. The TimeProvider 2700 includes a programmable 10 MHz or 1 PPS BNC port and a PPS+TOD RS422 on an RJ45 connection. Models with either dual DC or a single AC power input are available.
The TimeProvider 2700 offers the optional capability to accept PTP input and operate as an advanced boundary clock to complement and backup the GNSS signal. This option includes Symmetricom’s unique Automatic Path Asymmetry Compensation feature providing increased accuracy and stability in the PTP timing signal. An option for E1/T1 input/output is also available.