Kwashie Amartei Anang

Power Control and Performance Comparison of AODV and DSR Ad Hoc Routing Protocols

A technique is proposed to evaluate the effect of ambient noise and path loss have on received signal strength of mobile node in a mobile ad hoc network environment using optimized network (OPNET) simulator while comparing the performance of Ad-Hoc on demand distance vector (AODV) and dynamic source routing (DSR) protocols. Numerical and simulation results presented illustrate how the performance of an ad hoc network protocol drastically changes as a result of changing the mobility model and power control system of the network. The simulation result for DSR and AODV showed a significant improvement with 86.8% decrease in end-to-end delay (sec), while AODV also showed 68.5% drop in end-to-end delay. The network load simulation result revealed that DSR protocol maintained a constant load while there was a 75%drop in routing load for AODV protocol. The simulation results of AODV and DSR routing protocols showed 99%and 98%confidence intervals respectively.

Sensitivity of cellular wireless network performance to system & propagation parameters at carrier frequencies greater than 2 GHz

In this paper, mathematical analysis supported by computer simulation is used to investigate the impact of both system and propagation loss parameters on the performance of cellular wireless network operating at microwave carrier frequencies greater than 2 GHz, where multiple tier of co-channel interfering cells are considered to be active. The two-slope path loss model and the uplink information capacity of the cellular network is used for the performance analysis. Results show that for carrier frequencies greater than 2 GHz and smaller cell radius multiple tier of co-channel interfering cells become active as compared to carrier frequencies lesser than 2 GHz. The multiple tier of co-channel interfering cells, leads to a decrease in the information capacity of the cellular wireless network. The results also show that the system performance is sensitive to most of the propagation model parameters such as the basic and extra path loss exponent.

Minimum Cell Size for Information Capacity Increase in Cellular Wireless Network

In this paper results of mathematical analysis supported by simulation are used to find a theoretical limit for cell size reduction in mobile communication systems. Information capacity approach is used for the analysis. Attention is given to the active co-channel interfering cells. Because at microwave frequencies beyond 2 GHz, co-channel interfering cells beyond the first tier becomes dominant as the cell size reduces. We show that when the cell size limit is reached any further reduction in cell size will not increase the information capacity of the cellular network. A formula is derived for calculating the number of co-channel cells in subsequent tiers.

CELLULAR SYSTEM INFORMATION CAPACITY CHANGE AT HIGHER FREQUENCIES DUE TO PROPAGATION LOSS AND SYSTEM PARAMETERS

In this paper, mathematical analysis supported by computer simulation is used to study cellular system information capacity change due to propagation loss and system parameters (such as path loss exponent, shadowing and antenna height) at microwave carrier frequencies greater than 2 GHz and smaller cell size radius. An improved co-channel interference model, which includes the second tier co-channel interfering cells is used for the analysis. The system performance is measured in terms of the uplink information capacity of a time-division multiple access (TDMA) based cellular wireless system. The analysis and simulation results show that the second tier co-channel interfering cells become active at higher microwave carrier frequencies and smaller cell size radius. The results show that for both distance-dependent: path loss, shadowing and effective road height the uplink information capacity of the cellular wireless system decreases as carrier frequency increases and cell size radius R decreases. For example at a carrier frequency fc = 15.75 GHz, basic path loss exponent α = 2 and cell size radius R = 100, 500 and 1000m the decrease in information capacity was 20, 5.29 and 2.68%.

Adaptive MMSE multiuser receivers in MIMO OFDM wireless communication

This paper presents a novel adaptive multiuser detection scheme for MIMO OFDM, which we refer to as AMUD MIMO OFDM. It combines the adaptive minimum mean square error multiuser detection scheme with prior information of the channel and interference cancelation in the spatial domain. Simulation results show that joint channel parameters estimation has good performance compared to individual parameter estimation. The developed algorithm sum rate capacity is close to MIMO theoretical upper bound (21.5 bits/s/Hz at an SNR of 20dB) which indicates its applicability to the uplink channel, where power transmission at the mobile station is a constraint. The BER performance shows that an 8 x 8 AMUD MIMO OFDM provides a 2dB SNR gain as compared to non adaptive MIMO OFDM.

Sensitivity of information capacity of land mobile cellular system to propagation loss parameters at higher microwave frequencies

In this paper, results of mathematical analysis supported by simulation are used to investigate the impact of propagation loss on the performance and information capacity of cellular wireless network at higher microwave carrier frequencies (beyond 2 GHz). At higher microwave carrier frequencies co-channel interfering cells beyond the first six co-channel cell becomes active as the cell size reduces. It is shown that the second tier co-channel interfering cell is more dominant at lower (below 2.5) path loss exponent.

The performance of dynamic source routing protocol to path loss models at carrier frequencies above 2 GHz

In this paper, we describe a simulation study of the impact of wireless channel on Dynamic Source Routing (DSR) protocol performance at microwave carrier frequencies above 2 GHz. Simulation results show that at microwave carrier frequencies above 2 GHz, when the two-slope path loss model is used for channel modelling, the breakpoint distance affect the end-to-end throughput of the DSR protocol in Mobile Wireless Ad Hoc Network (MANET), whilst at frequencies below 2 GHz the end-to-end throughput for the free space and the two-slope path loss model was the same.

Optimised adaptive power on-demand routing protocol for mobile ad hoc wireless network

A technique is developed for ad hoc on-demand routing protocol. The protocol is based on the conventional on-demand ad hoc routing protocols with the addition of power model. The algorithm design and development is aimed to incorporate the transmitted power consumption function in such a manner that mobile nodes are able to evaluate their power status to decide if they are fit for packet forwarding and reception. This is illustrated through analytical approach supported by computer simulations over mobile ad hoc wireless network containing 80 mobile nodes. The results showed that power savings of 50% were achieved with no delay in the network and increased throughput performance by 60%, as compared to a network with conventional ad hoc on-demand distance vector and dynamic source routing protocols.

Power Consumption Analysis in Mobile Ad Hoc Networks

The central challenge in the design of ad-hoc wireless networks is the development of a dynamic routing protocol that efficiently finds routes between mobile nodes. Several network routing protocols such as Dynamic Source Routing (DSR), Ad Hoc On-demand Distance Vector (AODV) and Destination Sequence Distance Vector (DSDV) have been proposed to facilitate communication in a dynamically changing network area. Mobile Ad hoc Network (MANET) is faced with various challenges such as resource consumption during network routing operation. This paper present results from detailed power measurement studies of MANETs with emphasis on power consumption with different antenna designs. Computational simulation is used to analyse the power consumption in MANET on two platforms i.e. network configured with directional and omni directional antenna. The simulation results show that networks configured with directional antennas save 68% of the power as compared to networks configured with omni-directional antennas. While 99%packet delivery ratio were achieved with networks configured with directional antenna as compared to network with omni directional antenna.

Impact of Vehicular Traffic on Information Capacity of Cellular Wireless Network at Carrier Frequencies Greater Than 3 GHz

In this paper we describe a simulation study of the impact of vehicular traffic on the performance of cellular wireless network at microwave carrier frequencies above 3 GHz and up to 15 GHz, where the first and subsequent tiers co-channel interfering cells are active. The uplink information capacity of the cellular wireless network is used for the performance analysis. The simulation results show that vehicular traffic causes a decrease in the information apacity of a cellular wireless network. Results also show that for both light and heavy vehicular traffic environment, the nclusion of subsequent tier co-channel interferences caused a decrease of between 3 - 12