High-rate Wireless Personal Area Networks Research Articles

QoS-Guaranted Slot Allocation Algorithm for Efficient Medium Access in HR-WPAN

It is very important to provide a parameterized quality of service (QoS) using traffic specification (TSPEC), such as mean data rate, maximum burst size, and peak data rate, when packets from the application layer need to be transmitted with guaranteed services in a high-rate wireless personal area network (HR-WPAN). As medium resources are limited, the optimal medium time required for each device needs to be estimated to share the resources efficiently among devices. This paper proposes a variable-service interval-based resource allocation algorithm to efficiently make a reservation of medium resources based on a parameterized QoS. In other words, the proposed algorithm calculates the number of medium access slots (MASs) based on TSPEC, local resources, and local conditions and determines suitable locations for the MASs within a superframe to accommodate more devices. The simulation results show that the proposed algorithm can accommodate more devices and has greater than 10% resource allocation efficiency in an HR-WPAN compared to existing schemes.

TDMA based HR-WPAN Application for a Ship Area Network with Link Transmission Parameters Selection Algorithm

For a high-speed data transmission with guaranteed QoS and energy efficiency in a ship area network (SAN), we consider IEEE 802.15.3 based TDMA high-rate wireless personal area network (HR-WPAN) application. It is shown that the proposed SAN architecture with TDMA based HR-WPAN can provide a high quality wireless connectivity to the conventional dedicated wired devices and shipboard control network devices as a wireless gateway, by adaptively selecting transmission parameters such as transmission power and physical data rate for a fixed fragment size. Moreover, a realistic effect of ship building material such as steel (large ship) and FRP (medium size ship) is considered as a path loss parameter for performance evaluation. We demonstrated that the proposed TDMA based HR-WPAN system with the link transmission parameters selection algorithm could provide a good wireless network model applicable to the SAN architecture.

Channel State Information Based Distributed Reservation Protocol for Energy Efficiency in WiMedia Networks

Ultra wideband (UWB) technology has emerged as a solution for the wireless interface between medical sensors and a personal server in future telemedicine systems. The WiMedia Alliance has specified a distributed medium access control protocol based on UWB for high-rate wireless personal area networks. The legacy WiMedia standard must statically reserve an additional transmission time of 30 %, since transmission time is limited to network environment in wireless network. When channel environment is deteriorating badly, the additional reservation may not have enough time. Because the legacy WiMedia standard must wait the next reservation period if sending device does not transmit data frames in the current reservation period, the transmission delay occurs. Also, in a good channel environment, the additional reservation time results in a waste of performance. Therefore, there is a need to provide the reliability of data transmission as sending device predicts channel environment in WiMedia network and reserves the distributed reservation protocol (DRP) reservation duration considering the estimated channel environment. In this paper, we propose a novel resource reservation scheme considering channel environment in WiMedia network. The simulation results show that proposed protocol can enhance the throughput and delay performance and improve energy efficiency by minimizing the idle period of DRP reservation block.

A Robust Beacon Scheduling Scheme for Coexistence Between UWB Based WBAN and WiMedia Networks

Ultra wideband (UWB) technology has emerged as a solution for the wireless interface between medical sensors and a personal server in future telemedicine systems. The WiMedia Alliance has specified a distributed medium access control (D-MAC) protocol based on UWB for high-rate wireless personal area networks (WPANs). Also, the IEEE 802.15.6 standard for wireless body area networks (WBANs) allows that devices for healthcare and lifestyle applications are placed around and within the body. However, current WBAN devices cannot coexist with other home network systems or WPAN systems and cannot share wireless channel with the existing WiMedia devices, efficiently. Existing researches about coexistence are not suitable for WiMedia MAC protocol based on distributed architecture, since they focused on MAC protocol based on centralized architecture. Therefore, in this paper, we propose a robust beacon scheduling scheme for coexistence between UWB based WBAN and WiMedia networks. Using proposed scheme, WBAN devices can share the resource more efficiently with WiMedia devices and exchange data frames through the reserved BAN period duration.

A METHOD FOR PERFORMANCE MODELING AND EVALUATION OF LDPC DECODER ARCHITECTURE

This paper presents a high-throughput memory efficient decoder for low density parity check (LDPC) codes in the high-rate wireless personal area network application. The novel techniques which can apply to our selected LDPC code is proposed, including parallel blocked layered decoding architecture and simplification of the WiGig networks. State-of-the-art flexible LDPC decoders cannot simultaneously achieve the high throughput mandated by these standards and the low power needed for mobile applications. This work develops a flexible, fully pipelined architecture for the IEEE 802.11ad standard capable of achieving both goals. We use Real Time–Performance Evaluation Process Algebra (RT-PEPA) to evaluate a typical LDPC Decoder system's performance. The approach is more convenient, flexible, and lower cost than the former simulation method which needs to develop special hardware and software tools. Moreover, we can easily analyze how changes in performance depend on changes in a particular mode by supplying ranges for parameter values.

Computationally Efficient Single-Frequency Estimation Scheme in High-Rate WPAN Systems

Sub-optimal algorithms that avoid the complexity of the maximum likelihood scheme for estimating a frequency offset have been developed based on samples of the estimated auto-correlation function. However, their computation burden is still heavy for near-optimal performance. To overcome this problem, this paper proposes a reduced-complexity algorithm of single-frequency estimation for a high-rate wireless personal area network application. Accuracy and robustness of our frequency estimator are statistically assessed by Monte Carlo simulations. The results indicate that the proposed complexity effective algorithm closely conforms to the Cramer-Rao bound.

LDPC Decoder Modelling And Evaluation Using RT-PEPA

This paper presents a high-throughput memory efficient decoder for Low Density Parity Check (LDPC) codes in the high-rate wireless personal area network application. The novel techniques which can apply to our selected LDPC code is proposed, including parallel blocked layered decoding architecture and simplification of the WiGig networks. We use Real Time - Performance Evaluation Process Algebra (RTPEPA) to evaluate a typical LDPC Decoder system’s performance. The approach is more convenient, flexible, and lower cost than the former simulation method which needs develop special hardware and software tools. Moreover, we can easily analysis how changes in performance depend on changes in a particular modes by supplying ranges for parameter values.

와이미디어 통신네트워크의 멀티미디어 QoS 개선을 위한 분산협력방식 MAC 프로토콜 성능분석

In this paper, an efficient technique for enhancing the QoS of multimedia service for an WiMedia network applying distributed cooperative medium access (D-MAC) protocol is proposed. D-MAC protocol has been proposed to support high-rate Wireless Personal Area Networks (HR-WPANs) by the WiMedia Alliance. Unlike the centralized IEEE 802.15.3 MAC, the D-MAC UWB specified by WiMedia supports all devices to be self-organized and removes the SOP (Simultaneous Operating Piconet) problem, i.e., packet collisions between overlapped piconets in the centralized IEEE 802.15.3 MAC. However the WiMedia D-MAC can`t prevent reduce the throughput degradation occurred by mobile nodes with low data rate. Therefore, a distributed cooperative MAC protocol for multi-hop UWB network is proposed in this paper. The proposed technique can intelligently select the transmission path with higher data rate to provide real-time multimedia services with minimum delay, thus enhances QoS of multimedia service.

A Distributed Cooperative MAC Protocol for QoS Improvement and Mobility Support in WiMedia Networks

A Distributed Medium Access Control (D-MAC) protocol based on UWB for high-rate Wireless Personal Area Networks is specified by the WiMedia Alliance. D-MAC protocol is suitable for ubiquitous connection in home networks, military/medical applications due to its inexpensive cost, low power consumption, high data rate, and distributed approach. In contrast to IEEE 802.15.3, D-MAC makes all devices have the same functionality. And its networks are self-organized and provide devices with functions such as access to the medium, channel allocation to devices, data transmission, quality of service and synchronization in a distributed manner. D-MAC fundamentally removes the problems of the centralized MAC approach revealed at IEEE 802.15.3 MAC by adopting a distributed architecture. However, the current D-MAC can't prevent QoS degradations, occurred by mobile nodes with low data rate due to bad channel status, which cause critical problems in QoS provisioning to isochronous streams and mobile applications. Therefore, we propose a distributed cooperative MAC protocol for multi-hop WiMedia networks using virtual MIMO links. Based on instantaneous Channel State Information among WiMedia devices, our proposed protocol can intelligently select the transmission path with higher data rate to provide advanced QoS with minimum delay for real-time multimedia streaming services.

A 6b 1.2 GS/s 47.8 mW 0.17 mm265 nm CMOS ADC for High-Rate WPAN Systems

This paper proposes a 6b 1.2 GS/s 47.8 ㎽ 0.17 ㎟ 65 ㎚ CMOS ADC for high-rate wireless personal area network systems. The proposed ADC employs a source follower-free flash architecture with a wide input range of 1.0 V p-p at a 1.2 V supply voltage to minimize power consumption and high comparator offset effects in a nanometer CMOS technology. The track-and-hold circuits without source followers, the differential difference amplifiers with active loads in pre-amps, and the output averaging layout scheme properly handle a wide-range input signal with low distortion. The interpolation scheme halves the required number of pre-amps while three-stage cascaded latches implement a skew-free GS/s operation. The two-step bubble correction logic removes a maximum of three consecutive bubble code errors. The prototype ADC in a 65 ㎚ CMOS demonstrates a measured DNL and INL within 0.77 LSB and 0.98 LSB, respectively. The ADC shows a maximum SNDR of 33.2 ㏈ and a maximum SFDR of 44.7 ㏈ at 1.2 GS/s. The ADC with an active die area of 0.17 ㎟ consumes 47.8 ㎽ at 1.2 V and 1.2 GS/s.

IEEE 802.15.5 WPAN mesh standard-low rate part: Meshing the wireless sensor networks

This paper introduces a new IEEE standard, IEEE 802.15.5,which provides mesh capability for wireless personal area network (WPAN) devices. The standard provides an architectural framework enabling WPAN devices to promote interoperable, stable, and scalable wireless mesh topologies. It is composed of two parts: low-rate WPAN mesh and high-rate WPAN mesh. In this paper, we present only low-rate WPAN mesh because it is designed to support wireless sensor networks. IEEE 802.15.5 low-rate part is a light-weight scalable mesh routing protocol that caters well to the requirements of resource-constrained wireless sensor networks. By binding logical addresses to the network topology, IEEE 802.15.5 obviates the need for route discovery. This eliminates the initial route discovery latency, saves storage space and reduces the communication overhead and energy consumption. A distributed link state scheme is further built atop the block addressing scheme to improve the quality of routes, robustness, and load balancing. The routing scheme scales well with regard to various performance metrics. The standard also provides enhanced functions such as multicast, reliable broadcast, power saving, time synchronization, route tracing and portability. We also present the performance evaluation of major functions performed with a 50-nodes tested deployed over a whole floor (100 × 140 ft2) at CUNY Engineering building. The results testify that the IEEE 802.15.5 will serve well for wireless personal area networks and wireless sensor networks.

Cross-Layer Resource Allocation Scheme Under Heterogeneous Constraints for Next Generation High Rate WPAN

In the next generation wireless networks, the growing demand for new wireless applications is accompanied with high expectations for better quality of service (QoS) fulfillment especially for multimedia applications. Furthermore, the coexistence of future unlicensed users with existing licensed users is becoming a challenging task in the next generation communication systems to overcome the underutilization of the spectrum. A QoS and interference aware resource allocation is thus of special interest in order to respond to the heterogeneous constraints of the next generation networks. In this work, we address the issue of resource allocation under heterogeneous constraints for unlicensed multiband ultra-wideband (UWB) systems in the context of Future Home Networks, i.e. the wireless personal area network (WPAN). The problem is first studied analytically using a heterogeneous constrained optimization problem formulation. After studying the characteristics of the optimal solution, we propose a low-complexity suboptimal algorithm based on a cross-layer approach that combines information provided by the PHY and MAC layers. While the PHY layer is responsible for providing the channel quality of the unlicensed UWB users as well as their interference power that they cause on licensed users, the MAC layer is responsible for classifying the unlicensed users using a two-class based approach that guarantees for multimedia services a high-priority level compared to other services. Combined in an efficient and simple way, the PHY and MAC information present the key elements of the aimed resource allocation. Simulation results demonstrate that the proposed scheme provides a good tradeoff between the QoS satisfaction of the unlicensed applications with hard QoS requirements and the limitation of the interference affecting the licensed users.

A disturbed resource reservation structure for mobility and QoS support in WiMedia networks

A Distributed Meduim Access Control (D-MAC) protocol had been proposed to support High Rate Wireless Personal Area Networks (HR-WPANs) by the WiMedia Alliance. Unlike the centralized IEEE 802.15.3 MAC, the D-MAC UWB specified by WiMedia Alliance supports DRP (Distributed Reservation Protocol) mechanism which makes all devices be self-organized and removes the SOP (Simultaneous Operation Piconet) problem, i.e., packet collisions between overlapped piconets in the centralized IEEE 802.15.3 MAC. However, since each device's mobility perspective in multi-hop environment has not been taken into account in the current WiMedia D-MAC, it may cause a hidden node problem. In addition, once a DRP conflict occurs due to the mobile hidden node problem, only one of the DRP reservations involved in that DRP conflict maintains the reserved MASs, while other DRP reservations must be terminated and DRP negotiations for them have to be restarted although only a few Mass are overlapped. Such DRP termination and renegotiation time delays due to the DRP conflicts can be a critical problem to the mobile devices transceiving real-time QoS traffic streams. Therefore, we propose a mecahnism to provent and resolve multi-hop range DRP conflicts due to each device's mobility in D-MAC environment.

Effects of MB-OFDM System Interference on the Performance of DS-UWB

So far, two ultrawideband (UWB) standards have been proposed as high-speed physical technologies for next-generation wireless personal area networks (WPANs). These standards are based on multiband orthogonal frequency-division-multiplexing (MB-OFDM) UWB or direct-sequence UWB (DS-UWB). However, because of the withdrawal of the plan for a unique standardization process by the IEEE 802.15.3a task group (TG3a), these two technologies will coexist in the future. In this context, this correspondence provides a performance analysis of DS-UWB communication in the presence of MB-OFDM interfering transmissions, where the channel is modeled through the IEEE 802.15.3a standard model, and the network topology for the MB-OFDM interferers is based on a clustered structure as per the IEEE 802.15.3 descriptions for medium access control (MAC) and physical layer specifications for high-rate WPANs. The DS-UWB system performance is assessed in terms of bit error rate (BER). Specifically, an analytical expression for the average BER is derived, conditioned on the channel impulse response using a pulse collision model. Numerical and simulation results are provided and compared for different coexistence scenarios.

An RL-based scheduling algorithm for video traffic in high-rate wireless personal area networks

The emerging high-rate wireless personal area network (WPAN) technology is capable of supporting high-speed and high-quality real-time multimedia applications . In particular, video streams are deemed to be a dominant traffic type, and require quality of service (QoS) support. However, in the current IEEE 802.15.3 standard for MAC (media access control) of high-rate WPANs, the implementation details of some key issues such as scheduling and QoS provisioning have not been addressed. In this paper, we first propose a Markov decision process (MDP) model for optimal scheduling for video flows in high-rate WPANs. Using this model, we also propose a scheduler that incorporates compact state space representation , function approximation, and reinforcement learning (RL). Simulation results show that our proposed RL scheduler achieves nearly optimal performance and performs better than F-SRPT, EDD + SRPT, and PAP scheduling algorithms in terms of a lower decoding failure rate.

Feedback-assisted MAC protocol for real time traffic in high rate wireless personal area networks

During the past decade, there has been much standardization effort for indoor or shot-range networks, as communication devices and applications for such networks populate. As a prominent example of these activities, the IEEE 802.15.3 Task Group (TG) published a standard for high-rate wireless personal area network (HR-WPAN). To support strictly timed multimedia services, the TG adopts a time-slotted channel access protocol controlled by a central device (DEV). Although the channel time allocation algorithm plays a key role in deciding the network performance, it remains unspecified in the standard. Therefore, in this paper, we propose a novel feedback-assisted channel time allocation method for HR-WPAN. After initial channel times are allocated based on packet inter-arrival time statistics, the allocation is dynamically adjusted by utilizing feedback information from each DEV. The feedback information includes the buffer status, the packet transmission delay, and the physical transmission rate. By utilizing this feedback information, the central DEV can allocate sufficient channel time for transmissions of pending packets from a DEV. Moreover, the allocated channel times can be synchronized to the packet arrival times so that the overall transmission delay is reduced. To cope with time-varying wireless channels, a dynamic rate selection algorithm assisted by physical layer information is proposed in this paper. Performance evaluation is carried out through extensive simulations, from which significant performance enhancements are observed.

Dynamic resource allocation for supporting real-time multimedia applications in IEEE 802.15.3 WPANs

The IEEE 802.15.3 medium access control (MAC) protocol is an emerging standard for high-rate wireless personal area networks (WPANs), especially for supporting high-quality real-time multimedia applications. Despite defining quality of service (QoS) signalling mechanisms for interoperability between devices, IEEE 802.15.3 does not specify resource allocation algorithms that are left to manufacturers. To guarantee the QoS of real-time variable bit rate (VBR) videos and utilise the radio resource efficiently, the authors propose a dynamic resource allocation algorithm. The proposed bandwidth allocation algorithm is based on a novel traffic predictor. Recently, the variable step-size normalised least mean square (VSSNLMS) algorithm was employed for on-line traffic prediction of VBR videos. However, the performance of the VSSNLMS algorithm significantly degrades due to the abrupt traffic variation occurring at the scene boundary. To tackle this problem, the authors design a novel traffic predictor based on a simple scene detection algorithm and the VSSNLMS algorithm. Analyses using real-life MPEG video traces indicate that the proposed traffic predictor significantly outperforms the VSSNLMS algorithm with respect to the prediction error. The performance of the proposed bandwidth allocation algorithm is also investigated by comparing several existing algorithms. Simulation results demonstrate that the proposed bandwidth allocation algorithm surpasses other mechanisms in terms of channel utilisation, buffer usage and packet loss rate.

Scheduling algorithms for multimedia traffic over high-rate WPANs

The IEEE 802.15.3 standard aims at covering the gaps of current Wireless Personal Area Network (WPAN) technologies in supporting applications with very high-rate and/or quality of service requirements. To this end, the standard encompasses high-rate modulations and a flexible medium access mechanism that permits resource reservation. Whereas the standard defines the general resource management framework, the definition of practical scheduling algorithms is left open to proprietary solutions. In this paper we investigate the potentialities offered by the IEEE 802.15.3 framework for supporting multimedia services. More specifically, we analyze the performance of some classical scheduling policies in presence of intensive real-time and multimedia traffic, in order to identify the most effective strategy for the considered scenarios. The analysis has been performed by using a complete 802.15.3 C++ simulator, where we have realized the different scheduling strategies upon an entirely standard-compliant round robin polling procedure. Results show that the simple and well-known scheduling strategies considered in this study offer very good performance in a large set of realistic application scenarios.

Efficient scheduling techniques for high data-rate wireless personal area networks

Among several wireless network scenarios, the in-home environment is one of the more challenging in recent years. In particular, the Wireless Personal Area Network (WPAN) seems one of the most interesting application scenario as that networks work in small area for delivering multimedia traffic. The IEEE 802.15.3 is the emerging standard for WPAN. This standard is designed to provide low complexity, low cost and low power-consumption for personal area networks that manage multimedia traffic, video and audio between different devices in a small area environment. The piconet is the basic topology structure of a WPAN and it is defined as group devices where one of them is the PicoNet Coordinator (PNC). A PNC manages the synchronisation and controls the data traffic of the system. This paper proposes some scheduling techniques to be used at the Medium Access Control (MAC) layer for high data-rate WPANs. The proposed scenario is composed of several nodes generating both data and video traffic respecting the application scenario often foreseen for high-rate WPANs. Two scheduling methods are proposed which, exploiting the traffic growth, can improve the performance of the network in terms of throughput and delay. In particular the performance of an adaptive technique and an optimum technique are compared with the performance of the fixed technique considered in the standard.

Frame-Size Adaptive MAC Protocol in High-Rate Wireless Personal Area Networks

In this letter, we propose a frame-size adaptive MAC protocol for high rate wireless personal area networks (WPANs). In the proposed scheme, during communication, frame error rate is periodically reported to a transmitting device and the frame size is changed according to the measured results. Thus, the channel can be more effectively utilized by adapting to variable radio conditions. Analytical results show that this scheme achieves a much higher throughput than a non-frame-size adaptive media access control protocol in high-rate WPANs.