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This paper describes new algorithms for mobile backbone network optimization. In this hierarchical communication framework, mobile backbone nodes (MBNs) are deployed to provide communication support for regular nodes (RNs). While previous work has assumed that MBNs are unconstrained in position, this work models constraints in MBN location. This paper develops an exact technique for maximizing the...
The IEEE Task Group has approved recently the 802.11p amendment to enable efficient short range communications for vehicular networks by introducing multiple enhancements at the physical and MAC layer. It defines a control frequency channel for control and most critical data packets and one or several service frequency channels for less critical packets. In this paper, we propose an analytical model...
Multihop relaying in WiMAX networks is considered a cost effective way to extend the coverage of the base stations, increase cell capacity, or both. In this paper, we consider deploying non-transparent relay stations for coverage extension and study the issue of fairness schemes in such networks. Since there are access and relay zones in both downlink and uplink frames and simultaneous transmissions...
Error control techniques in wireless links such as Automatic Repeat Request (ARQ) and Forward Error Correction (FEC) are still quite effective approaches in the improving system throughput in particular in time-varying channel environments. In this paper, a dual-branch selection diversity receiver of combining Selective Repeat-ARQ scheme and BCH channel coding (hybrid ARQ) in mobile cellular networks...
In recent years, Mobile Ad hoc Networks (MANETs) are continuing to attract the attention for their potential use in several fields. Mobility and the absence of any fixed infrastructure make MANETs very attractive for mobility and rescue operations and time-critical applications. In this paper, we present the implementation and analysis of our implemented MANET testbed considering the Optimized Link...
Biologically inspired networking paradigm introduces throughput gains in an adaptive and robust operation over the classical routing algorithms designed for mobile ad hoc networks (MANETs). However, this performance gain comes at the price of additional overhead as in the case of ant routing protocols. In this context, we present the Scented Node Protocol (SNP) to reduce the overhead requirement while...
Tactical communication architectures are evolving to support mobile broadband multimedia in NLOS environments. Multihop wireless systems have the potential to improve coverage and capacity over single-hop radio access systems. The IEEE 802.16 standard, also known as WiMAX, is a recent long-range broadband technology with mobility support, and the IEEE 802.16j substandard extends the range of mobile...
Video streaming for IPTV is transferring to wireless mobile devices. This process poses questions of the video quality that will result and the suitability of the existing pseudo-streaming schemes for video transfer. This paper sets out the case for wireless broadband video streaming based on a simple negative acknowledgment (NACK) scheme, which for convenience is called broadband video streaming...
Wireless mobile multimedia communications are being greatly increased in the number of users, diversity of applications and interface technologies. Future mobile based Internet will accommodate various wireless technologies and also will need to provide sufficient end-to-end QoS (Quality of Service) mechanism to provide enhanced user's satisfaction. In this paper, we propose a new adaptive end-to-end...
This paper analyzes the problems in the wireless network caused by using minimum hop count as its routing metric, and discusses ETX metric which invented by De Couto to solve these problems and the shortage of it in mobile environment, then modifies it by relatively counting as to make it suitable for such environment. This paper uses the new ETX as a metric for the OLSR routing protocol, and proves...
In this paper, we extends bandwidth balancing technique in wired networks to operate in mobile ad hoc networks (MANETs). In bandwidth balancing in Distributed-Queue-Dual-Bus (DQDB), different nodes occupy the same channel, and information about the bandwidth is transferred between nodes in the unused bandwidth. Similarly, in wireless networks, the capacity on a channel is shared by several sources...
We propose two scheduling and resource allocation schemes that deal with Quality of Service (QoS) requirements in Uplink Long Term Evolution (LTE) systems. QoS for a multiclass system has been seldom taken into account in previous resource allocation algorithms for LTE uplink. In one of the new algorithms, we investigate the possibility of assigning more than one resource block and its consequences...
The congestion control scheme plays a critical role in the multicast communication. Without a proper congestion control mechanism, multicast protocols would cause unfairness while sharing network bandwidth with other flows. We propose a deliberated congestion control scheme to multicast multimedia contents for smart phones retrieving effectively. Our key idea is to detect the single trip time of packet...
The performance of traditional TCP congestion control protocol degrades when congestion and contention increase in ad hoc networks that use the IEEE 802.11 DCF. Many of the problems result from medium contention at the media access control (MAC) layer. In this paper, we present a new contention-based congestion control (CBCC) method according to a novel congestion information from MAC layer. This...
Femtocells are expected to increase network capacity, extend macrocell coverage, and introduce new services. Because femtocells share the same frequency band with macrocells in many cases, the femtocell base station (BS) must mitigate the interference with macrocells as well as ensure coverage in customer premises. However, conventional femtocell BS transmit power setting have not adequately accounted...
This paper proposes an analytical model for the throughput of the Enhanced Distributed Channel Access (EDCA)mechanism in IEEE 802.11p MAC sub-layer. Features in EDCA such as different Contention Windows (CW) and Arbitration Interframe Space (AIFS) for each Access Category (AC), and internal collisions are taken into account. The analytical model is suitable for both basic access and the Request-To-Send/Clear-To-Send...
Future wireless access will involve a variety of integrated and interworking technologies. Depending on the conditions (e.g., the specific application, the quality of service requirements, the user mobility) each session will be served through the most suited access network; following some event, there will be a variation of the access technology, which is called vertical handover. Although the use...
We report on field trials using CoMP transmission in the downlink of a mobile radio network. Two new features enable over-the-air CoMP transmission from physically separated base stations and terminals. These are distributed synchronization and a fast virtual local area network. Using VLAN tags, terminals feed back the multi-cell channel state information to their serving bases where it is multiplexed...
We have already proposed a hybrid single-carrier (SC) and multi-carrier (MC) system for next-generation mobile communication system. A SC signal has low peak-to-average power ratio (PAPR), which yields high power output for wide coverage. A MC signal is robust against frequency-selective fading and has high data rate with quadrature amplitude modulation (QAM). By appropriately selecting SC and MC...
Future cellular mobile radio networks will exhibit a much more dense base station deployment than 2nd or 3rd generation communications systems, particularly with regard to traffic coverage. Hence, a significant increase in power consumption of cellular networks can be expected. In order to counter this trend, energy efficiency of such networks should be increased considerably. Concerning energy efficiency,...
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