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One of the most popular applications of IEEE 802.16 network is to serve as a backhaul service for IEEE 802.11 networks. However, the traffic of an IEEE 802.16 connection aggregated from IEEE 802.11 networks fluctuates. Thus, efficient bandwidth reservation at the subscriber station (SS) is an importance issue. This study proposes a simple and flexible bandwidth reservation scheme at the SS, called...
This paper presents simulation of WiMAX based system under jamming. The performance of the system was found out to greatly differ with the use of different jamming signals, allowing central areas to be identified, where system development should be focused on. In addition, from the basic theory point of view, rather surprising results were also found. This work should give a clear picture of how the...
Earliest Deadline First (EDF) is a delay-optimal scheduling algorithm which is commonly used in real-time applications such as Voice over IP (VoIP) and Video on Demand (VoD) in wired and wireless networks. EDF calculates the deadline of a packet as follows: the latency parameter provided by the subscriber during admission control is added to the arrival time of the packet to form the packet deadline...
Broadband Video Streaming (BVS) with selective retransmission trades a reduced but acceptable video quality during IEEE 802.16e hard handoff (HHO) for improved end-to-end latencies. Both forms of BVS promise better video quality with an HHO than UDP transport or traditional congestion-controlled streaming.
The ability to support quality of service (QoS) for a wide range of applications that exhibit different service requirements is a major competency of IEEE 802.16 networks. One of the keys to QoS provision is a scheduling algorithm that is able to determine the service ordering for packets from different service classes. This however is undefined in the standard to promote innovation by equipment vendors...
This paper demonstrates robust video streaming for IPTV over WiMAX. In the proposed method, an H.264/AVC video bit-stream is data partitioned according to data priority. Raptor channel coding is adaptively applied to the partitioned data. In the event of outright packet drops, redundant partition bearing packets serve to protect priority data. Further, to guarantee a minimum acceptable level of video...
As intelligent content management of IPTV moves popular material nearer to the end-user, application-layer channel coding schemes, involving retransmission of extra redundant data, become attractive. Application-layer, adaptive rateless channel coding is exploited in this paper's scheme to reconstruct streamed video across an IEEE 802.16e (mobile WiMAX) channel. The paper concentrates on the trade-offs...
This paper proposes a new handover mechanism between WiMAX and WLAN networks. It can support low latency by simplifying re-authentication process during handover. The proposed scheme allocates MA ID (Mobile Agent Identifier) as AAA key during initial connection establishment to WiMAX or WLAN. The MA ID plays a role as general AAA key which enables the MN to access to all ANs (Access Networks) connected...
Designing a heterogeneous network including systems providing different QoS, such as the emerging WiMAX, is a difficult task. The integration of a WiMAX access system with Differentiated Services (DiffServ) enhances the overall performance of the network. This paper investigates the interworking between WiMAX and DiffServ networks, by measuring one-way delay, jitter and packet drop rate of VoIP traffic...
This paper proposes a new scheduling algorithm for IEEE 802.16-2005 Broadband Wireless Metropolitan Area Networks in TDD mode. The proposed algorithm focuses on solving the problem of handling high priority traffic in congested networks while minimizing starvation conditions for other served classes. In this work, a detailed simulation study is carried out for the proposed scheduling algorithm as...
Low handover latency and IP session continuity are envisioned to be important factors for realizing next-generation all-IP heterogeneous wireless networks. To meet these constraints of the next generation networks, Proxy Mobile IPv6 (PMIPv6) has been considered as one of the IP mobility management protocols in recent years. Much research about the performance analysis of PMIPv6 has been done. However,...
In this paper, we propose an effective contention-based bandwidth request scheme to differentiate the contention scheme of each quality of service(QoS) type in IEEE 802.16e systems. Especially, the scheme is focused on the improvement for extended real-time polling service(ert-PS). The proposed scheme allows the ert-PS to use multicast polling in the normal condition, but to adopt both multicast and...
The need to respond to congestion and channel loss over not one but two wireless links is an impediment to video streaming between one mobile user device and another via an intervening IP network. The result can be poor wireless channel utilization and interruptions to the streaming process. This paper proposes that multi-connection streaming will avoid the need for application-specific cross-layer...
Although the IEEE 802.16 standard defines various QoS classes and their associated parameters, it does not define the scheduling, routing, and Call Admission Control (CAC) algorithms to be used in the network. It is left unstandardized for vendor differentiation. Currently, scalable distributed scheduling and routing algorithms are available for IEEE 802.16 mesh networks. But, the existing CAC algorithms...
The increasing demand for shared awareness in multi-platform sensor systems requires advanced wireless information sharing techniques. The analysis of these techniques requires information about communication resources and latency to be available in models. The work presented here introduces generic low complexity models that describe the probability of latency and the required resources in terms...
Radio channel measurements in the 2-6 GHz frequency band were performed in two different outdoor environments including the dense urban environment in Manchester and the rural/semi-rural environment of Ipswich. The data were analysed to obtain rms delay spreads for sectored antennas as well as to estimate channel functions for time domain and frequency domain channel simulators of the IEEE802.16-d...
Wireless data services, boosted by the massive use of popular Internet-based services such as email, WWW, etc., wireless wideband networks capable of supporting mobile multimedia services have attracted increasing intention in last few years. An important requirement has been postulated for these wideband services — they cannot be substantially more expensive than the voice services offered today...
With the evolution of wireless systems from traditional circuit switch technology to packet based technology there is a requirement that voice be maintained to an acceptable level of quality such that user experience does not become compromised. All next generation wireless networks have been specified as packet switched radio networks which imply that the flaws of traditional packet based networks...
In IEEE 802.16 networks, bandwidth allocation is centralized at the base station (BS). For the uplink traffic, data transmission is scheduled after the BS processes bandwidth requests (BW-REQs) sent by mobile stations (MSs). In this paper we focus on the multicast/broadcast polling method, where MSs send their BW-REQs during contention periods. Contention-based polling is deemed suitable for Best-Effort...
Opportunistic scheduling has been recognized as an effective method that significantly outperforms fixed TDMA scheduling in both channel capacity and communication reliability. Nevertheless the superior system performance comes at a price of high computational complexity, large signaling overhead, and unfairness among users. In this paper, we find that in relay-assisted next-generation wireless networks,...
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