In Sync


Sync over Packet for the implementation of WiMAX
The IEEE 802.16 Worldwide Interoperability for Microwave Access (WiMAX) standard is rapidly being positioned as the core technology for next-generation data centric broadband mobile wireless applications. Designed for providing QoS, WiMAX can be used for the implementation of a transport network suitable for real-time applications like Internet access, streaming services, interactive gaming, video-on-demand, and voice-over-IP (VoIP) services. With the introduction of Mobile WiMAX (IEEE 802.16e), a new foundation had been set for the emerging 4G networks.

WiMAX is supporting both FDD and TDD modes of operation. However, TDD is the preferable mode
of operation for data centric applications and for Mobile WiMAX as its spectral efficiency is higher than FDD. In addition, TDD is easier to pair with smart-antenna technologies, it provides enhanced flexibility, and it is assymetrical in nature.

When using TDD mode, the whole spectrum is alternately used for transmit (Tx) or for receive (Rx). Therefore, in order to avoid interferences between Tx and Rx, the IEEE 802.16 has defined two guard bands: TTG - Transmit/Receive guard band and RTG - Receive/Transmit guard band.

For that reason, WiMAX and in particular IEEE 802.16e have the most demanding synchronization requirements. WiMAX base stations requires three level of synchronization: Frequency, Phase, and Phase Lockup. WiMAX phase lockup requires that all base stations will be synchronized to one another within
±1usec in order to avoid adjacent base stations interferences.

Currently, the solution for maintaining this strict synchronization performance is by using a GPS receiver at each WiMAX base station. A new cost effective solution is now becoming available with the emerging IEEE 1588v2 standard which supports all three levels of synchronization required by TDD as well as the required tight synchronization performance.


A new approach for clock synchronization implementation over packet is required to leverage the IEEE 1588v2 capabilities in order to handle the inherent Ethernet/IP/MPLS packet network impairments in order to meet clock synchronization performance as defined by the IEEE 802.16 standard. IPCLOCK IPC2713 Sync over Packet Engine (SoPE) for IEEE 1588 is a the solution for the implementation of WiMAX base station synchronization over Ethernet/IP/MPLS networks.