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Spectrum awareness is one of the most challenging requirements in cognitive radio (CR). To adequately adapt to the changing radio environment, it is necessary for the CR to be able to perform joint detection and classification of low signal-to-noise ratio (SNR) signals. In this paper we propose a joint detection and classification algorithm for the mobile Worldwide Interoperability for Microwave Access...
Interest in Broadband Wireless Access (BWA) has been growing due to its high speed data rate, wide area coverage and support for Quality of Service (QoS) requirement for different applications. There is a need for better scheduler to handle diversified QoS while increasing system efficiency. In this paper, we propose an Improvised-Modified Deficit Round Robin (I-MDRR) that not only meets the QoS requirements...
IEEE 802.16 WiMAX provides high data rate but limited coverage area and 3G is well established network with low data rate as comparison to WiMAX network. So if we will combine both WiMAX and 3G network then it provides ubiquitous high speed data access as well as attract wider user base. In this paper we have taken component which is used in interworking architecture, security consideration, authentication...
Since the IEEE 802.16 first standard was proposed in 2004 to provide broadband wireless service, the standard has not only been widely studied, but also broadly commercialized. The current IEEE 802.16-2009 standard document specifies five Quality of Service classes. As is typical with most standards, IEEE 802.16 does not require the use of a specific scheduler. In this paper, we first evaluate the...
One of the fundamental requirements for IEEE 802.16/WiMAX, to become a key technology for high-speed multimedia service delivery, is QoS (Quality of Service) differentiation. Although different types of QoS classes have been defined by the IEEE 802.16 standard, the scheduling architecture is left to be vendor specific. In this paper, new modifications are purposed, and a detailed simulation study...
IEEE 802.16 mesh mode is positioned to be used as a wireless backbone network. In coordinated distributed scheduling (C-DSCH), when nodes transmit control messages to compete for channel access, they need to wait for some period of time called hold-off time to compete again. Network performance is sharply affected by the hold-off mechanism in the bandwidth reservation procedure. In this paper, a new...
The demand of multimedia services has extensively increased in conjunction with the popularity of the smart phone and the deployment of high speed broadband wireless networks. Especially, the video telephony service is one of the most used multimedia services. It has a stringent quality-of-service (QoS) requirement including high data rate and low latency among multimedia services. Therefore the optimizing...
The existing IEEE 802.16 is a series of Wireless Broadband standards known as WiMAX as an important technology for providing high-speed Internet access to home and business subscribers in a wide area cellular network. It has defined real time and non-real time services. But the standard does not specify transmission scheduling schemes to support the services. In order to support the delay sensitive...
Heterogeneous radio network which efficiently utilizes the resources of multi-radio access systems is one of promising approaches for flexible, reliable and high-capacity communication. Regarding the cooperative controlling functionality in the heterogeneous system, two schemes are considered to be applicable to the efficient usage of multi-radio systems. One is a link selection and the other is a...
A 2–2 cascade multirate sigma delta modulator targeting for GSM/ Bluetooth/ GPS/ WCDMA/ WLAN/ WiMAX application is designed in this paper. According to the needs of the customers and desired Quality of Service, the proposed modulator should be a power and area efficient reconfigurable sigma delta modulator with variable bandwidth and dynamic range. The multirate technique is introduced in the modulator...
This paper considers the energy saving problem of IEEE 802.16e networks which consist of a base station and multiple mobile stations. The mobile station may establish one or multiple connections that have specific QoS requirements, including a bandwidth requirement and delay bounds. Since the mobile station turns off the transceiver to save energy when all connections of the mobile station enter sleep...
Wimax (Worldwide Interoperability for Microwave Access) is a promising technology which can offer high speed data, voice and video service to the customer end, which is presently, dominated by the cable and digital subscriber line (DSL) technologies. The performance assessment of Wimax systems is dealt with. The biggest advantage of Broadband wireless application (BWA) over its wired competitors is...
This paper addresses the Common Radio Resources Management of a Heterogeneous Network composed of three different Radio Access Network (RANs): UMTS, Wi-Fi and Mobile-WiMAX. The network is managed by an algorithm based on a priority table, user sessions being steered preferentially to a given RAN according to the service type. Six services are defined, including Voice, Web browsing and Email. A time-based,...
As Internet IPTV extends to mobile devices, suitable transport protocols are sought that can adapt streaming to wireless access networks. This paper proposes a semi-reliable video-rate protocol that provides selective retransmission of scalable video layers should channel packet loss occur. The semi-reliable protocol leads to good video quality and reduces end-to-end delay and start-up delay.
For providing multimedia streaming services in a mobile WiMAX network, it is important to not only optimize the power consumption of mobile stations (MSs) but also satisfy the QoS requirements of the streams. This paper studies the problem of optimizing the power consumption of the mobile stations (MSs) in the cell of a base station (BS) where each MS has several uplink and downlink connections of...
We propose a block scheduling (BLS) scheme which can significantly reduce signaling overhead to accommodate more users with low-rate, real-time traffic. The basic concept of the BLS scheme is to allocate the resource to each user by using resource blocks which are a basic unit of resource allocation. Since the performance of the BLS scheme depends on traffic models, we consider two types of traffic:...
Initial ranging (IR) involves detecting the binary phase shift keying (BPSK) code transmitted by the new subscriber station (SS). In this paper, we formulate a simple detector using the Neyman-Pearson theorem (NPT) for single-code detection in IEEE 802.16-compliant time division duplex (TDD) orthogonal frequency division multiple access (OFDMA) systems. Exploiting the BPSK structure in the ranging...
Scheduling is a fundamental component in resource (bandwidth and power) management in NG wireless networks and plays the main role in providing QoS requirements such as delay, throughput and packet loss for different classes of service in 802.16d networks. In this paper we propose a novel scheduling algorithm Strict Priority Based Adaptive modulation and Coding (SP_AMC_Based) that can grantee QoS...
Multiuser diversity combined with Orthogonal Frequency Division Multiple Access (OFDMA) are a promising technique for achieving high downlink capacities in new generation of cellular and wireless network systems. The total capacity of OFDMA based-system is maximized when each subchannel is assigned to the mobile station with the best channel to noise ratio for that subchannel with power is uniformly...
In this paper we propose a new random channel access protocol to reduce the channel access delay in a multichannel orthogonal frequency division multiple access (OFDMA) wireless networks. In particular, we propose a two dimensional random walk through time and frequency domain slots simultaneously to reduce the random channel access delay for the IEEE 802.16e-2005 based WiMAX media access control...
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