Papers by Borhanuddin Mohd Ali
Wireless Personal Communications, 2013
In this paper, a proposed new wireless protocol so-called wireless controller area network is int... more In this paper, a proposed new wireless protocol so-called wireless controller area network is introduced. WCAN is an adaptation of its wired cousin, controller area network protocol. The proposed WCAN uses token frame scheme in providing channel access to nodes in the system. This token frame method follows the example used in wireless token ring protocol which is a wireless network protocol that reduces the number of retransmissions as a result of collisions. This scheme based on CAN protocol allows nodes to share a common broadcast channel by taking turns in transmitting upon receiving the token frame that circulates around the network for a specified amount of time. The token frame allows nodes to access the network one at a time, giving 'fair' chance to all nodes instead of competing against one another. This method provides high throughput in a bounded latency environment. The proposed WCAN protocol has been developed and simulated by means of QualNet simulator. The performances of this proposed protocol are evaluated from the perspective of throughput, end-to-end delay and packet delivery ratio, and are compared against the IEEE 802.11 protocol. Simulation results show that the proposed WCAN outperforms IEEE 802.11 based protocol by 62.5 % in terms of throughput with increasing network size. Also, it shows an improvement of 6 % compared to IEEE 802.11 standard at a higher data interval rate.
Wireless Networks, 2013
A new technique for multi-cell joint channel estimation (MCJCE) in time division code division mu... more A new technique for multi-cell joint channel estimation (MCJCE) in time division code division multiple access based on singular value decomposition (SVD) reduced rank technique is proposed in this paper. MCJCE is one of the effective solutions to improve the mobile system performance throughout mitigate the inter-cell interference form the neighboring cells. The increasing complexity of multi-cell system model due to the additional processing of the interferer users will be solved by using SVD reduced rank technique, where a limited number of parameter that really need it to describe the channel matrix will be estimated. Two models of multi-cell approaches are discussed, the first one depended on reconstruct the convolutional midamble matrix of inactive users in serving cell by the strongest interferer users from the neighboring cells. The second one will be more inclusive to user traffic scenarios in mobile systems and will be expanding to contain all detected users. The simulation results prove the validity of the proposed reduced rank technique for precision channel estimation (6.4 and 5 dB) and (9 and 7 dB) for case 1 and 2 respectively; BER performance improvements over the conventional estimators.
Internet Engineering Task Force (IETF) working group has standardized the transmission of interne... more Internet Engineering Task Force (IETF) working group has standardized the transmission of internet protocol version 6 (IPv6) packets over IEEE 802.15.4 low power wireless personal area network (LoWPAN) as 6LoWPAN protocol. It provides the wireless sensor network (WSN) node with IP communication capabilities by putting an adaptation layer above the 802.15.4 link layer. Different mechanisms performed by adaptation layer require the 6LoWPAN header encapsulation in the packet. Although routing is among the key issues of 6LoWPAN research, the way to encapsulate a new routing header in the 6LoWPAN packet has yet been investigated thoroughly. In this paper, different ways of routing header encapsulation in 6LoWPAN protocol stack is discussed. The simplified version Ad-Hoc On-Demand Distance Vector (AODV) such as On-Demand Distance Vector (LOAD) and Dynamic MANET On-demand for 6LoWPAN (DYMO-low) have currently been proposed in 6LoWPAN routing. Hierarchical routing (HiLow) is another routing protocol that is used in 6LoWPAN to increase the network scalability. Some comparisons of these routing protocols have been made in terms of their routing metric such as number of hops count. The used control messages for the route discovery in different routing protocols have also been investigated. These comparisons show that each routing protocol has its own advantage depends on the involved applications. There are some tradeoffs of respective routing protocols. The routing protocol that uses hello message may provide more reliable but results a higher delay in the packet routing.
Agile-SD is one of the latest versions of loss-based congestion control algorithm (CCA), which ha... more Agile-SD is one of the latest versions of loss-based congestion control algorithm (CCA), which has been proposed to improve the total performance of transmission control protocol (TCP) over high-speed and short-distance networks. It has introduced a new mechanism, called agility factor mechanism, which shortens the epoch time to reduce the sensitivity to packet losses and in turn to increase the average throughput. Agile-SD has only been tested via simulation; however, it has not been mathematically proven or evaluated. The contribution of this paper is twofold. First, a new mathematical model for the throughput of NewReno and Agile-SD is proposed. This model is designed using the well-known Markov chains to validate the correctness of Agile-SD and to show the impact of buffer size, multiplicative decrease factor, and maximum limit of agility factor (λ max) on the total performance. Second, an automated algorithm configuration and parameter tuning (AACPT) technique is employed to optimize and automate the configuration of λ max. Furthermore, the numerical results for both NewReno and Agile-SD are compared with the simulation results, in which the validity of the proposed model is confirmed. Moreover, the output of the AACPT is exploited to formulate a new equation, which calculates the optimal λ max from a given β in order to conserve the standard interface of the TCP. This equation increases the scalability of Agile-SD and improves its total performance.
Proceedings of the Asia-Pacific Advanced Network, 2013
The 17th Asia Pacific Conference on Communications, 2011
Theoretically, IEEE 802.15.4 is more suitable for resource-constraint ad-hoc network because of i... more Theoretically, IEEE 802.15.4 is more suitable for resource-constraint ad-hoc network because of its low power consumption characteristic. However, performance of IEEE 802.11 is unknown if its transmission power and receiver sensitivity are limited to match those levels of IEEE 802.15.4. In this paper, the performance evaluation of IEEE 802.11 against IEEE 802.15.4 with those power levels is presented. The transmission
articles by Borhanuddin Mohd Ali
This paper presents a novel low-complexity technique for reducing the Peak-to-Average Power Ratio... more This paper presents a novel low-complexity technique for reducing the Peak-to-Average Power Ratio (PAPR) in Orthogonal Frequency Division Multiplexing (OFDM) systems followed by an efficient hardware co-simulation implementation of this technique by using a Xilinx system generator on a Field Programmable Gate Array (FPGA). In this technique, each subblock is interleaved with the others, and a new optimisation scheme is introduced in which the number of iterations is equal only to the number of subblocks, which results in reduced processing time and less computation that, in turn, leads to reduced complexity. Furthermore, the proposed method focuses on simplifying the required hardware resources. Thus, it can be easily combined with other simplified techniques. The simulation results demonstrate that the new technique can effectively reduce the complexity up to 98.22% compared with the new existing Partial Transmit Sequence (PTS) techniques and yield a good Bit Error Rate (BER) performance. Through the comparison of performance between simulation and hardware, it is distinctly illustrated that the designed hardware block diagram is as workable as the simulation and the difference of the result is only 0.1 dB.
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Papers by Borhanuddin Mohd Ali
articles by Borhanuddin Mohd Ali