Interoperability of GPON and WiMAX for network capacity enhancement and resilience

Abstract

This paper was published in Journal of Optical Networking and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://www.opticsinfobase.org/JON/Issue.cfm. Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law. Copyright Optical Society of America.The interoperability of standard WiMAX and GPON is shown to overcome the wireless spectrum congestion and provide resilience for GPON through the use of overlapping radio cells. The application of centralised control in the optical line terminal (OLT) and time division multiplexing for upstream transmission enables efficient dynamic bandwidth allocation for wireless users on a single wavelength as well as minimised optical beat interference at the optical receiver. The viability of bidirectional transmission of multiple un-coded IEEE802.16d channels by means of a single radio frequency (RF) subcarrier at transmission rates of 50 Mbits/s and 15 Mbits/s downstream and upstream respectively for distances of up to 21 km of integrated GPON and WiMAX micro-cell links is demonstrated

Advanced PON topologies with wireless connectivity

“…At the OLT after WiMAX symbols are generated by multiple transmitters they are upconverted to a subcarrier for each wireless-enabled ONU. The FDM technique was used to ensure signal transparency for various radio signal formats and to avoid interference with the GPON spectrum [2]. Each WiMAX transmitter at the OLT is serving a single radio cell at an ONU/BS that is divided into small parts called sectors in order to make the cell more efficient in terms of reduced co-channel interference and increased capacity.…”

“…between Sector 2 and Sector 1 of ONU/BS2 and ONU/BSn respectively in Fig. 1, operating at different frequency channels enabled by centralised processing in the OLT [2]. Therefore, users that are in the overlapping regions can have simultaneous wireless support from multiple ONU/BSs, thus increasing the capacity of the WiMAX network and providing redundancy in case of fibre failure between a distribution node and an ONU due to established alternative routes for signal transmission.…”

“…In order to demonstrate the capability of the architecture to transmit WiMAX channels successfully over combined GPON and radio-cell links a physical layer simulation test-bed was implemented using Virtual Photonic Inc. (VPI) and MATLAB [2]. It has been previously established that non-linear effects of the optical modulators can degrade RoF transmission in terms of error vector magnitudes (EVMs) and bit error rates (BERs) [2].…”

“…It has been previously established that non-linear effects of the optical modulators can degrade RoF transmission in terms of error vector magnitudes (EVMs) and bit error rates (BERs) [2]. …”

“…WiMAX and LTE, represents the challenge for ubiquitous broadband multimedia communications. A novel architectural platform demonstrating the transparent transmission of radio signals over standardized passive optical network (PON) topologies has been investigated in that direction [2]. The application of Radio over Fibre (RoF), for enhanced network redundancy and capacity through centralised management, is in the focus by means of accessing each remote Optical Network Unit/BaseStation (ONU/BS) from the optical line terminal (OLT) by frequency division multiplexing (FDM).…”