Relay Technologies in IEEE 802.16j Mobile Multi-hop Relay (MMR) Networks

IEEE 802.16 standard is created to compete with cable access networks. In the beginning end users are immobile and have a line of sight with base station, now it moved to mobile non line of sight (NLOS) with the new standard IEEE 802.16e and IEEE 802.16j. The new IEEE 802.16j standard which is an amendment to IEEE 802.16e is mobile multi hop relay (MMR) specification for wireless networks. This paper discusses relay modes, relay transmission schemes and relay pairing schemes of IEEE 802.16j. Relay technologies such as transparent relay modes, non transparent relay mode, relay pairing schemes such as centralized relay pairing schemes, distributed relay pairing scheme, characterises of relay based networks such as throughput enhancement, capacity increase, cost reduction , relay techniques such as time domain frequency domain relay techniques and relay placement are also discussed in this paper. The paper also discusses about integration of IEEE 802.16j with IEEE 802.11. Keywords: IEEE 802.16j, Relay pairing schemes, relay techniques, Relay modes, WIMAX, NCTUns, et

Problems faced in Communicate set up of Coordinator with GUI and Dispatcher in NCTUns network simulator

Distributed Emulation can be carried out between real world applications with a simulator. NCTUns-6.0 is a simulator based on kernel re-entering and distributed Emulation simulation methodology, with this methodology a more realistic network model can be simulated for real time applications. Coordinator is a Program that sets up communication between the GUI and Dispatcher in NCTUns-6.0 I, a network simulator running on Fedora-13. We have given in this paper how problems faced in communication set up of Coordinator with  GUI and Dispatcher are overcomed . This paper focuses on how to overcome the above problems and execute simulations in real time. This paper also deals with KDE, SELINUX, iptables, environment variables and X-server for NCTUns-6.0 simulation engine Keywords: Coordinator, Dispatcher, nctunsclient, NCTUns-6.0, Fedora-12, SELinux, IPtable

Throughput Enhancement in IEEE 802.16j Mobile Multi-hop Relay (MMR) Networks

IEEE 802.16 standard is created to compete with cable access networks. In the beginning end users are immobile and have a line of sight with base station, now it moved to mobile non line of sight (NLOS) with the new standard IEEE 802.16e and IEEE 802.16j. The new IEEE 802.16j standard which is an amendment to IEEE 802.16e is mobile multi hop relay (MMR) specification for wireless networks. In this paper we have proposed a new model for throughput enhancement, optimal relay placement and spatial reuse techniques. We have used four mobile stations (T-MS) connected to transparent mode base station (TMR-BS), which are moving at a speed of 20 m/sec. The T-MS are initially placed near to TMR-BS and are moving away from TMR-BS. The average throughput achieved without relay T-RS is 800 Kbps and the average throughput achieved with relay T-RS is 1300 Kbps. There is 40 % increase in the throughput by placing transparent mode relays T-RS at suitable position

NCTUns Simulation model for IEEE 802.16j Mobile multi hop Relay (MMR) WIMAX networks

IEEE 802.16j Mobile multi hop relay (MMR) network was approved in the year 2009, by the IEEE 802.16 working committee. In IEEE 802.16j Relay station with same capacity as that of Base station is used to extend the coverage area of base station or used to increase the Throughput capacity of base station. In this paper we have given a simulation model for IEEE 802.16j MMR networks using the NCTUns -6.0 network simulator. The simulation model can be used for carry out IEEE 802.16j WiMAX simulations. The NCTUns network simulator is an open source simulator, and it used real time data to carry out the simulation. NCTUns uses a distributed architecture to support remote and concurrent simulations. The NCTUns has 8 components such as GUI, simulation engine, dispatcher, coordinator, kernel level modification, User level demean, parallel simulations for carry out IEEE 802.16j MMR network simulation. Key-Words: - Relay modes, IEEE 802.16j, NCTUns-6.0, transparent mode, non-transparent mode, et