Introduction
This case study provides an overview of how a large satellite and data communications service provider implemented a cost effective, location diverse antenna installation for Ka-Band satellite data transmissions by using a DWDM RF over Fiber Solution.
Challenge
High-throughput Satellite (HTS) technology operating in Ka-Band offers significant advantages over conventional satellite networks operating in Ku-Band and other lower frequencies as more bandwidth is available at the higher Ka-Band frequencies. However, adverse weather conditions negatively impact the higher (26.5-40 GHz) Ka-Band frequencies causing service interruptions and performance degradations.
Solution
In order to mitigate the impacts of adverse weather conditions, the system was designed with local and remote antenna sites. The remote antenna site was located 200 kilometers away from the local site providing location diversity to offset the effects of the adverse weather conditions at either site. The Time Division Multiple Access (TDMA) channel access method delivered precise time synchronization of the local and diverse route ensures hitless signal switching.
The solution was implemented using off-the-shelf Dense Wave Division Multiplexing (DWDM) products from the DEV Optribution family of products:
- The versatile DEV 7113 space saving chassis that is able to house up to 16 optical DWDM transmit modules (DEV 7251), or up to 20 optical receive modules (DEV 7333)
- EDFA optical amplifier modules are also available for the DEV 7113 chassis
- To ensure synchronization in time, a delay line is used for the local route (DEV 7859)
- To control the remote antenna site equipment, DEV implemented a 1 GBit Ethernet Link over fiber
The DEV solution provides first-class quality in terms of optical transmission while meeting all requirements and being highly reliable and readily serviceable, for example:
- Optical Tx-Rx-Modules, EDFA, redundant power supplies and the control module are hot swappable Additional modules are installed in Cold Standby for the event of failure
Results
The DEV optical DWDM system that the customer deployed ensured uninterrupted service for the high bandwidth HTS Ka-Band system by connecting signals from the local and remote antennas. DEV worked closely with the customer in the design and realization phase of the project providing technical expertise to solve various challenges including:
- Ensuring proper isolation and handling of the signals of the up and down links within the DWDM transmission
- Ensuring proper signal transmission independent of weather conditions
- Delivering a 1 GBit Ethernet Link for remote equipment management within the RF over Fiber System
- Designing and implementing a delay line to synchronize the signals from the local and diverse antennas
Conclusion
A location diverse synchronized antenna installation is essential to overcome adverse weather and environmental conditions for HTS Ka-Band systems. DEV provided a scalable solution in terms of numbers of antennas and distance to the remote antenna site. RF over Fiber using DWDM technologies can readily provide distances of 200 km between the main and diverse antenna sites. DEV provided the customer a space efficient and cost effective turnkey system solution.