bluuebunny/crossref_metadata_2025 huggingface dataset:
An efficient and dependable protocol for critical MANETs
Authors: Elgohary Ashraf , Sobh Tarek S. , Nouh Sayed A. , Zaki M.
Published: December 2019

Critical MANET environments such as military battlefields and disaster recovery operations impose a number of requirements such as the need for robustness and performance within high mobility scenarios; also, they impose some constraints such as Hostile attacks, RF range and cost, battery limitations.

We studied the core-based routing protocol PUMA, in addition to two ant-based routing protocols MANHSI and AAMRP to identify their drawbacks while working in critical MANETs. Finally, we propose a novel routing protocol named Adaptive Secure Headship Following Induction Keeping (ASHFIK) to work ideally in critical MANETs scenarios.

In this paper, we discuss the structure of ASHFIK, which uses a new mechanism called the Headship Mechanism, which provides always a standby core to work if the original core is down. After studying performance analysis of ASHFIK compared to PUMA, we can conclude that ASHFIK is particular suitable for most critical MANETs scenarios.
A high-performance QoS-enhanced proportional fair scheduling algorithm over downlink OFDMA-based networks
Authors: Chao I-Fen , Chiou Chuei-Sheng
Published: December 2019

OFDMA-based networks have been considered to be a promising solution to wireless networks especially for broadband multimedia mobile services. The major challenges pertaining to such OFDMA-based networks are to design a medium access control scheme that is expected to exploit multi-channel multi-rate diversity and with QoS provision. The previous existing scheduling algorithms either target at maximizing system throughput while starving the low-rate users, or focus on throughput fairness but seriously decreasing the system throughput. While proportional fair (PF) has emerged as a prominent candidate in wireless networks, as it achieves a good tradeoff between system throughput and fairness, PF still leads to low throughput of bad channel users, resulting in limiting the attainable QoS throughput for the entire system.

In this paper, we propose a QoS-enhanced proportional fair (QEPF) scheduling algorithm, which aims at maximizing QoS throughput while still retaining fairness as well as maximizing system throughput in downlink OFDMA networks. QEPF proposes a QoS-enhanced PF-based utility function, which supports QoS and is a low-complexity algorithm for multi-channel OFDMA networks. We demonstrate via extensive simulation results, that QEPF outperforms PF in terms of system throughput and mean delay. The results illustrate that QEPF surprisingly attains great performance for poor channel users, while not sacrifices the performance of good channel users. Furthermore, the results show that QEPF well accommodates nearly twice the amount of high priority data than PF does.
Service Burstiness and Dynamic Burstiness Measures: A Framework
Authors: Cruz Rene L.
Published: December 2019

We introduce a framework for characterizing service disciplines in terms of service burstiness. A wide range of service disciplines recently proposed for high-speed integrated services networks fall within this unifying framework. We introduce dynamic burstiness measures, and use them to describe the relationship between the burstiness of traffic entering a server, the burstiness of traffic exiting a server, the service burstiness of a server, and queueing delay. This relationship can be exploited to characterize end-to-end network delay in terms of the burstiness of traffic sources, the burstiness of traffic arriving at destinations, and the servi.ce burstiness of the servers which comprise the network. In addition, new classes of service disciplines are presented which support delay guarantees as well as efficient statistical sharing.
Congestion Control in High Speed Networks via Alternate Path Routing
Authors: Sidhu Deepinder , Abdallah Shukri , Nair Raj
Published: December 2019

This paper presents a congestion control scheme based on alternate path routing. In the scheme, if a node encounters congestion or loses its preferred neighbor on its primary path to a destination, it sends data packets to that destination over precomputed alternate paths. The scheme ensures that data packets do not travel in loops and limits the spread of congestion to neighboring nodes. Simulations of the scheme show that alternate path routing reduces the number of dropped packets, achieves a more uniform link utilization and alleviates congestion in networks under light to moderate loading. When using alternate path routing, it is observed that the loss ratio closely follows the load ratio which is not true when using shortest path routing.
Connection Management in High-Speed Interconnection Systems
Authors: Chlamtac Imrich , Kienzle Martin G.
Published: December 2019

High-speed interconnection systems for linking high-performance computers with each other and with their intelligent peripheral devices have gained great importance in recent years. The HIPPI standard which governs the interfaces to most of today's high-speed interconnection systems is a representative, standardized interconnection solution and its control and performance issues are consequently of particular interest. This paper examines the issue of connection management control for these interconnection systems. It describes the interconnection system environment, the characteristics of the traffic being carried, and the ensuing problem of efficient connection management. Different management policies are described, ranging from policies that require a complete knowledge of the whole interconnection system's state for their operation, to policies operating with only local client state knowledge. Considerations relevant to performance and switch implementation complexity trade-offs of the different policies are presented. Finally, priority access supporting connection management policies using preemptive and non-preemptive disciplines are described, and for the first time compared, using an analytic model introduced in this paper. Comparison of the two disciplines gives insights useful in choosing the preferred connection management policy and priority discipline, as a function of implementation objectives, the system's particular traffic characterization and its performance requirements.
Switching Latency Impact on Star-Coupled WDM Photonic Network Pre-Allocation Protocol Performance
Authors: Bogineni Kalyani , Sivalingam Krishna M. , Dowd Patrick W.
Published: December 2019

This paper evaluates the performance of two pre-allocation protocols when the switching latency of the wavelength tunable optical devices required for WDM networks is not negligible. The channels are pre-allocated to the nodes with the approach, where each node has a home channel that it uses either for all data packet transmissions or all data packet receptions. This approach reduces the resulting system complexity since both tunable transmitters and receivers are not required, and also has the advantage of being applicable to systems where there are many more nodes than wavelength channels. Switching latency is the time required by the tunable optical devices to tune to the required destination wavelength. The performance impact of switching latency on a generalized random access protocol is compared to an approach based on interleaved time multiplexing. Both protocols are designed to operate in a multiple-channel multiple-access environment and require each node to possess a tunable transmitter and a fixed (or slow tunable) receiver. Semi-markov analytic models are developed to investigate the performance of the two protocols. The analytic models are validated through extensive simulation. The performance is evaluated in terms of network throughput and packet delay with variations in the number of nodes, data channels, packet generation rate, and switching latency.
A Critique of ATM from a Data Communications Perspective
Authors: Cidon Israel , Derby Jeff , Gopal Inder , Kadaba Bharath
Published: December 2019

Fast Packet Switching (FPS) is emerging as the preferred technology for future high speed, integrated networks. Asynchronous Transfer Mode (ATM) is an approach to FPS that is in the process of standardization and is the preferred approach of the carrier community. Concurrently, alternative approaches to FPS based on variable sized packets have been proposed by segments of the data communication industry. These approaches include Frame Relay and an approach developed by IBM called PARIS. The purpose of this paper is to examine the suitability of ATM for data communications relative to some of these alternative approaches.
Multigigabit, Multichannel Lightwave Networks Using Subcarrier Multiplexing
Authors: Olshansky R. , Bugos A. R. , Hofmeister R. T.
Published: December 2019

A novel multigigabit, multichannel lightwave network is described which uses subcarrier multiplexing to place multiple information channels and a baseband control channel on a single optical carrier. The control channel uses an FDDI-like token-passing access protocol and a 100 Mb/s control channel to provide efficient access to many Gb/s of information. The subcarrier multiplexed network (SCM-NET) can simultaneously transport many forms of information including variable-length data-grams, ATM-cells, and connection-oriented video traffic. By channelizing the total throughput, the reduction in utilization efficiency caused by propagation delay between nodes is significantly improved relative to conventional single-channel gigabit networks.
Security for SMDS CNM
Authors: Kostick Deirdre , Tesink Kaj
Published: December 2019

Switched Multi-megabit Data Service (SMDS) is a high-performance, public, packet-switched data service. Offered as a public network equivalent of a MAC level service, the datagram transport offered by SMDS is as easily integrated into existing networking protocol architectures as Local Area Network (LAN) or Metropolitan Area Network (MAN) technologies such as Ethernet and Fiber Distributed Data Interface (FDDI). A Customer Network Management (CNM) service has been defined to be offered in conjunction with SMDS. SNMP has been selected as the subscriber access method for the CNM service, which because of the wide acceptance of SNMP, allows for easy integration of the CNM service into the overall management of customer networks. As a public service, SMDS CNM requires special considerations in the area of security. This paper discusses these considerations, and describes the services and mechanisms that have been defined for secure access to SMDS SNM.
Atomic: A High-Speed Local Communication Architecture
Authors: Felderman Robert , DeSchon Annette , Cohen Danny , Finn Gregory
Published: December 2019

ATOMIC is an inexpensive high-speed LAN built by USC/ISI. It is based upon Mosaic technology developed for fine-grain, message-passing, massively paraIiel computation. Each Mosaic processor is capable of routing variable length packets, while providing added value through simultaneous computing and buffering. ATOMIC adds a general routing capability to the native Mosaic wormhole routing through store-and-forward and path concatenation. ATOMIC aggregate bandwidth scales as the number of nodes increases, and it has a small interface cost. Each ATOMIC channel has a data carrying capacity of 480 Mb/s. A prototype ATOMIC LAN has been constructed along with host interfaces and software that provides full TCP/IP compatibility. Using ATOMIC, 1500-byte packets have been exchanged between hosts at an aggregate transfer rate of more than 1 Gb/s. Other tests have demonstrated throughput of 5.25 million packets per second over a single Mosaic channel. The architecture is flexible both in topology and functionality. This paper describes the architecture and performance of ATOMIC.
Bandwidth Allocation for Broadband Multichannel Systems
Authors: Ren Zhixing , Meditch James S.
Published: December 2019

Future broadband networks will need to support transmission and switching at rates ranging from hundreds of Gbits/s to a Tbits/s or more. A feasible approach in the realization of such networks is the use of sets of parallel links or channels which are termed trunk groups or channel groups. In this paper, we examine an optimal bandwidth allocation scheme for multichanne1 systems to switch trunk groups. This new multichannel switching system features a simple architecture, high throughput, high channel utilization, and other properties such as preserving packet sequence, being robust to unbalanced input traffic loads, providing fair access to network transmission resources, and fast packet processing via a pipeline structure. Numerical results show that the multichannel system can achieve a throughput of 91% per channel for a trunk group of 32 channels while also providing very low average cell delay performance in the presence of correlated inputs.
Priority Performance of Banyan-Based Broadband-ISDN Switches
Authors: Tridandapani Srini , Meditch James S.
Published: December 2019

A practical fast packet switching module for use in B-ISDN switching architectures is described. The module is built around a self-routing banyan network which employs dilation and replication to enhance throughput. The differing requirements of delay and loss sensitivity for various traffic types are handled by assigning priorities to packets. A new result in the form of the throughput equation of lower priority packets in a banyan network which is improved by dilation, replication, and internal speed-up is presented. The delay versus throughput analysis shows that the switch module is capable of handling integrated voice-data-video traffic efficiently.
Analysis of a Markov-Modulated Fluid Model for Multimedia Traffic with Loss and Delay Priorities
Authors: Krunz Marwan , Hughes Hennan
Published: December 2019

This paper presents a complete fluid-flow analysis of a traffic control mechanism in an ATM multiplexer, known as Nested Threshold Cell Discarding with Multiple Buffers. NTCD/MB is a buffer management scheme that implements loss and delay priority queueing strategies in order to satisfy a wide range of quality-of-service requirements. We consider a heterogeneous mix of traffic which consists of real-time traffic with a stringent cell delay requirement, and nonreal-time traffic with a stringent cell loss requirement. Moreover, a proportion of real-time cells has an additional stringent loss requirement. Cell arrivals are mode led using a fluid-flow modeling approach. The system we analyze consists of two buffers interacting via a common server. The steady-state probability distribution for the buffers' content as well as other performance statistics are obtained. Our approach is based on computing the conditional probability distributions of the buffers and using this information to find the desired unconditional stationary distributions. This approach can be used, in general, to analyze multiple dependent systems of buffers. Numerical examples based on the analysis are used along with simulations to study the performance of NTCD/MB. It is shown that NTCD/MB can be used effectively to provide performance guarantees on different cell loss and delay requirements of the traffic.
Schemes for Slot Reuse in a Dual Bus System with the CRMA II MAC
Authors: Sharon Oran , Segall Adrian
Published: December 2019

Several schemes for slot reuse in CRMA II when implemented on the Dual Bus configuration are studied. They are all based on cancellations to confirmations that downstream stations transmit to upstream stations due to slot reuse, thus enabling a better use of the reserved slots. A correctness proof is supplied for the schemes, together with simulation results which show a better performance of the new schemes over the original one.
Distributed Coordinated Deflection Routing Algorithms for High Speed Networks
Authors: Bona Raffaele , Davoli Franco , Di Febbraro Angela
Published: December 2019

The deflection routing problem for a high speed network is dealt with, where every packet must be associated with one output port at the instant of its arrival at a switching node. Conflicts occur whenever two or more should be sent through the same output port. The algorithm proposed to solve such situations coordinates locally optimal strategies, based on instantaneous information, via a mechanism to exchange information among the nodes. Such a coordination is performed by making each node pass some aggregate information, regarding the traffic ‘congestion’ in the downstream portion of the network, to its predecessors. The algorithm is first stated in its optimal version, which may require a significant computational overhead. For this reason, a suboptimal, but computationally efficient version of the algorithm is also introduced. Some simulation results are presented to compare the performance of both versions of the algorithm with those of other routing policies previously proposed in the literature.
A Set of Multicast Primitives for Fault Tolerant Distributed Systems
Authors: Pagani Elena , Rossi Gian Paolo
Published: December 2019

Reliable multicast among the members of a group is recognized as an important service to support emerging multimedia and distributed applications, These applications have a variety of multicast requirements that may be matched with the semantics of the multicast primitives provided by an underlying layer.

This paper deals with the design and the implementation of a high level set of multicast primitives that combine both message ordering and message atomicity semantics. The primitives provide uniform agreement in a synchronous environment in which both omission and crash failures may occur. We introduce a novel algorithmic approach through which the normal processing of the messages can be performed together with the recovery actions that are required to cope with failures. As a consequence, under failure conditions the algorithms perform better in terms of both network load and throughput. Nonetheless, a comparable behaviour under reliable conditions is ensured. Furthermore, by using a stable storage as part of the fault tolerance method, the algorithms autonomously distinguish amongst permanent (crashes) or transient (omission) failures. This makes them independent of the underlying transport service and adaptable to different protocol suites.

The paper also contains the analysis of the performances obtained from the initial implementation of the described primitives.
ATMTraP: An ATM Traffic and Performance Measurement Tool
Authors: Johnston Cesar A. , Smith David J. , Young Jr. Kenneth C.
Published: December 2019

This paper presents an experimental prototype ATM traffic and performance measurement tool known as ATMTraP. ATMTraP collects traffic information, which can then be analyzed to provide source and link characterization and ATM network element performance. The prototype tool consists of dedicated hardware components and an X Window-based user interface that allow for the collection, display and analysis of ATM traffic statistics. Initial experiments using ATMTraP have been carried out in the Nectar Gigabit Testbed for different traffic sources including a Cray C-90 supercomputer, an iWARP systolic array and a HIPPI-equipped Sun workstation.
A neurocomputing approach to congestion control in an ATM multiplexer
Authors: Tarraf A. , Habib I. , Saadawi T.
Published: December 2019

This paper presents a new approach to the problem of congestion control arising at the User-to-Network Interface (UNI) of the ATM-hased Broadband Integrated Services Digital Networks (B-ISDN). Our approach employs an adaptive rate-based feedback control algorithm using reinforcement learning Neural Networks (NNs). We show that this new approach is very effective in limiting the buffer's occupancy levels and hence, minimizing congestion episodes. Moreover, the statistical multiplexing gain is greatly enhanced as more sources can be supported over the same buffer. The reinforcement learning NN controller provides an adaptive optimal control solution. This is achieved via the formulation of a performance measure function (cost function) that is used to, adaptively, tune the weights of the NN. The cost function is defined in terms of two main objectives: 1) to minimize the Cell Loss Rate (CLR), i.e., control congestion, and 2) to preserve the quality of the voice/video traffic via maintaining the original coding rate of the multimedia sources. The output of the NN controller is fed-back to the input sources, to throttle their arrival rates via reducing the coding rate (i.e., decreasing the number of bits per sample). Simulation results show that the NN control system is adaptive in the sense that it is applicable to different types of multimedia traffic. Also, the control signal maximizes the performance of the system which is defined in terms of its performance measure function.
Self-stabilizing end-to-end communication
Authors: Awerbuch Baruch , Patt-Shamir Boaz , Varghese George
Published: December 2019

Self-stabilizing protocols must begin operating correctly even when started from an arbitrary state. The end-to-end problem is to ensure reliable message delivery across an unreliable network under the weakest possible guarantee from the network – that the sender and receiver are never separated by a cut of permanently failed links. In this paper we present the first self-stabilizing end-to-end protocol. Our solution has message complexities comparable with the best known non-stabilizing solutions. Our solution also has good stabilization time complexity: the time for the protocol to stabilize has the same complexity as the time the protocol takes to deliver a message.
A high-performance priority scheme for ATM switching systems
Authors: Chen Wen-Tsuen , Hwang Wu-Yuin
Published: December 2019

In this paper, cell loss priority schemes in the ATM switches are studied. Many schemes had been proposed to manage buffer access for priority classes. However, these schemes suffered from poor buffer utilization or prohibitive implementation complexity. Therefore, we propose a simple priority scheme called Separate logic Queues with Complete buffer Sharing (SQCS). In the SQCS scheme, buffers are shared by priority classes and two service strategies, First-Come-First-Service (FCFS) and High-Priority First (HPF), are employed to serve priority classes. The performance of our proposed scheme is evaluated and compared with those of other priority schemes. The results indicate that our proposed scheme has a better performance and low implementation complexity. Hence, the SQCS scheme is an effective priority scheme for the ATM switching system.
Protocols to eliminate tuning penalties for packet-switched WDM star networks with large tuning latency
Authors: Wu Jieh-Chian , Willner Alan E. , Silvester John A.
Published: December 2019

The use of low-speed tunable devices may lead to throughput and delay penalties for packet-switched WDM star networks. When the tuning latency is significant, conventional cost-effective solutions result in significant throughput and delay penalties. Our approach: (i) combines and unifies existing approaches to improve performance by pipelining multiple tunable filters per node and making a TDM schedule with maximum time gap for reception; (ii) introduces ‘superpackets’ (multiple packets with the same source and destination), thereby relaxing the impact of large tuning latency. Since the superpackets increase throughput at the cost of increased delay, we determine the minimum delay, under a constraint of no throughput penalty. A discrete-time queueing model of the protocol shows that a system with two tunable filters per node has low delay and is wavelength-efficient for uniform traffic.
Performance evaluation of the MetaRing MAC protocol carrying asynchronous traffic
Authors: Anastasi G. , Lenzini L.
Published: December 2019

This paper analyzes in depth the asynchronous part of the MetaRing MAC protocol by considering a network configuration (hereafter scenario) in which the slot reuse capability is used to the minimum extent possible. The MetaRing MAC protocol behavior is first analyzed in asymptotic conditions (i.e., when each station is trying to seize all the medium capacity), then in underload conditions (i.e., when the offered load is lower than the maximum achievable aggregate throughput), and finally in overload conditions (i.e., when the offered load is slightly higher than the maximum achievable aggregate throughput). Our results show that the MetaRing is unfair and that the unfairness depends, in particular, upon the workload parameters, in addition to the K and L protocol parameter values. Our analysis includes medium capacities in the range 150 Mbps-2.4 Gbps.
The impact of mapping wander on the performance of SDH TU-11 and TU-l2 uniform pointer processors
Authors: Sholander Peter E. , Owen Henry L.
Published: December 2019

Pointer processors in Synchronous Optical Networks (SONET)/Synchronous Digital Hierarchy Networks (SDH) may be placed into three categories: fixed threshold pointer processors, adaptive threshold modulation pointer processors and uniform pointer processors. Fixed threshold pointer processors produce gapped pointer sequences during SONET/SDH holdover mode when one or more node's clock has lost its synchronization reference. These gapped pointer sequences cause mapping wander in the underlying PDH payloads. This wander has motivated the development of uniform pointer processors which reduce/remove the gaps caused by the STM-n, AU and TU overhead bytes. However, uniform pointer processors cannot remove the additional gapped pointer effects caused by the VC overhead bytes. This paper reviews previous mathematical analysis and simulation results for SDH networks which use fixed threshold pointer processors to transport E1 PDH payloads in VC-12. That analysis is then extended to SDH networks which transpOlt DSl in VC-11. Next, a uniform pointer processor algorithm is proposed for the case where VC-12 transports an E1 rate PDH payload. Finally, a lower bound on the Maximum Time Interval Error (MTIE) that can be achieved with a uniform pointer processor is calculated.
A novel and simple beforehand bandwidth reservation (BBR) MAC protocol for OBS metro ring networks
Authors: Chen Wen-Ping , Wang Wen-Fong , Hwang Wen-Shyang
Published: December 2019

This paper proposes a novel and simple MAC protocol called beforehand bandwidth reservation (BBR) to reserve the empty slots in the next big-slot cycle for OBS ring networks by control channel. The node architecture uses one tunable transmitter and one fixed receiver to add or drop data channels and a fixed transmitter/receiver pair to transmit and receive on the control channel. Each node possesses a dedicated channel to receive data, so it inherently occupies a priority position. Fortunately, a well-known packet scheduling approach, time-division multiplexing (TDM), can overcome this problem. In addition, the length of the big-slot cycle is studied with a view to investigating performance divergence. Finally, a multi-token protocol using the (FTW–FRW) node architecture is compared with the BBR protocol. According to simulation results, the BBR scheme using the TDM approach achieves the best bandwidth utilization (more than 95%), while the multi-token protocol achieves the worst performance based on packet distribution in the MCI backbone.
A network traffic prediction approach based on multifractal modeling
Authors: Vieira Flávio Henrique Teles , Bianchi Gabriel Rocon , Lee Luan Ling
Published: December 2019

This work extends the notion of the widely mentioned and used fractional Brownian traffic model in the literature. Extensive experimental investigations indicate that the proposed traffic model, named extended fractional Brownian traffic, can capture not only the self-similar properties, but also the inherent multifractal characteristics of those traffic flows found in modern communication networks. Additionally, the structure of this traffic model is taken into account in a traffic prediction algorithm that benefits from the more accurate traffic modeling. The experimental results clearly point out the advantages of using the proposed model in traffic modeling as well as in traffic prediction.
Flow-based packet-mode load-balancing for parallel packet switches
Authors: Shi Lei , Li Wenjie , Liu Bin
Published: December 2019

Parallel Packet Switch (PPS) is broadly used in designing large-capacity switching fabrics, since it resolves the bottlenecks of scheduling algorithm, memory bandwidth, and serial transmission technology simultaneously. Current packet-based load-balancing algorithms for PPS cannot preserve intra-flow packet orders without costly reordering mechanisms. In this paper, we study the feasibility of flow-based packet-mode load-balancing algorithm, which thoroughly avoids packet out-of-order. Through performance analysis based on traffic model from real-trace, we show that given moderate speedups, all the three proposed flow-based algorithms can provide throughput and delay guarantees under admissible traffic input. Trace-driven simulations are carried out to verify our results.
Calculating approximate blocking probabilities for TDM wavelength optical networks with OTSIs
Authors: Huei Yoong Cheah , Keng Pung Hung , Krivulin Nikolai
Published: December 2019

Previous works have proposed analytical models of TDM wavelength networks to evaluate the blocking performance, but they differ in their underlying assumptions and have varying computation complexities. In this paper, we propose an analytical model of TDM WDM optical networks with optical time-slot interchangers and without wavelength converter for minimum fixed hop routing. In order to make the analysis tractable, we propose a schema that work for any number of partition patterns regardless of numbers of links, wavelengths in each link, and time-slots in each wavelength. Our analytical model provides good accuracies in individual routes and average network blocking probability when compared with the simulation results.
An optimized energy saving mechanism in IEEE 802.16e Mobile WiMAX systems
Authors: Baker Alaa M. , Ng Chee Kyun , Noordin Nor Kamariah , Mustafa Ahmed , Akbari Ayyoub
Published: December 2019

The IEEE 802.16e standard defines a sleep mode operation for conserving power to support the battery life of mobile broadband wireless access (BWA) devices. The system saves energy when it goes through a sleep period with some delay in packet arrival response time. The relationship between energy consumption and the delay is studied to ensure best performance for mobile devices. This relationship has been analyzed by using a mathematical model. A new scheduling method is proposed to adjust the sleep cycle periods by adding a small increase to the next sleep cycle compared with the previous cycle instead of just simply doubling the previous cycle. The simulated results were obtained after adjusting the length of the first sleep cycle period (Tmin ). Adjusting Tmin  provides a result of 54% reduction in the time needed for every frame to get a response especially in a lower traffic region. In a high traffic region, a reduction of 21.5% has been obtained in energy consumption for each sleep mode operation. Therefore, the proposed idea confirms a faster frame response time at lower energy consumption.
High-speed dynamic TDMA arbiter for inter-layer communications in 3-D network-on-chip
Authors: Khan Mohammad Ayoub , Ansari Abdul Quaiyum
Published: December 2019

The conventional two-dimensional (2-D) integrated circuit (IC) has limited scope for floor planning and therefore limits the performance improvements resulting from the Network-on-Chip (NoC) paradigm. The arrangement of 3-D also offers opportunities for new circuit architecture based on the geometric capacity that provide greater numbers of interconnections among multi-layer active circuits. The emerging 3-D VLSI Integration and process technologies allow the new design opportunities in 3-D NoC. The 3-D NoC can reduce significant amount of wire length for local and global interconnects. The role of bus and arbitration logic is equally important in the design of NoC. The performance of the traditional bus is degraded by the increasing number of processing elements and transaction oriented model [On-Chip Communication Architectures, Morgan Kaufmann, 2008]. This has attracted much attention for applying wireless network protocols as CDMA, TDMA, dTDMA, etc. in SoC. The TDMA systems use a fixed number of timeslot. This protocol wastes bandwidth when some timeslots are allocated but not used. The dynamic TDMA (dTDMA) bus arbiter dynamically grows and shrinks the number of timeslots to match the number of active transmitters [in: VLSI Design, 2006. Held jointly with 5th International Conference on Embedded Systems and Design, 19th International Conference on, January 2006, p. 8]. In this paper, we present a design of high-speed switch and layer arbiter for inter-layer communications in 3-D Network-on-Chip. We have developed a Register Transfer Logic (RTL) level simulation model to evaluate the performance of proposed arbiter. A 640-bit message with uniform random destination data pattern was injected per IP per machine clock cycle. The worst case latency for the proposed design is 35 clock cycles. The presented architecture demonstrates their superior functionality in terms of speed and latency compared with existing implementation. The design is synthesized using 0.18 micron TSMC Technology [Taiwan Semiconductor Manufacturing Company, Ltd, 2011].
Routing with a density-based probabilistic algorithm for mobile ad-hoc networks
Authors: Ong Hean-Loong , Natsheh Essam , Wan Tat-Chee
Published: December 2019

Ad-hoc networks can operate even when there is a scarcity of network infrastructure. This research examines ad-hoc networks that have varying node densities. These environments can be found in areas struck by disasters to urban city environments. Mobile nodes would not distribute evenly in such environments. Instead, the nodes would likely concentrate around specific landmarks or areas such as public squares with a high number of pedestrians while connecting roads and highways that have a low density of mobile nodes. The main contribution was the integration of a density based probabilistic scheme on AODV to reduce incurred routing overheads and improve packet delivery without significantly affecting the throughput and end to end delays. The proposed AODV–P (AODV–Probabilistic) protocol was compared against the AODV and OLSR protocols via simulation. The evaluation was based on three different environments: a high density, a variable density and a sparse density. The study showed that the AODV–P had a 28% higher data throughput than AODV and a 42% higher data throughput than OLSR at the three environments. Other performance parameters also showed that AODV–P performed better than AODV or OLSR in sub-optimal network environments due to the improved link lifetimes and lower routing overheads.
Improving the performance of P2P networks using SPIS with Query Filtering
Authors: Sadish Sendil M. , Nagarajan N.
Published: December 2019

The need of simple storage access, bandwidth and processing power of computers located at the edges of the network is highly required in advanced computing. Peer to Peer (P2P) satisfies the functional requirements of several applications. The searching of the content and file sharing is perhaps the most popular application of P2P networks. In this application, flooding is used as the prevailing resource location method for content searching and file sharing. Larger volume of unnecessary traffic in the network is created due to flooding mechanism. It is because a peer may receive the same queries multiple times through different paths. In this paper, the performance of the searching is analyzed and improved using the proposed method namely Super-peer based Innovative Search (SPIS). In this method, the super-peer maintains the local peer's information; in addition it maintains other super-peer's information for reducing the unnecessary search in the P2P networks. During the searching, the number of query packets creates a local traffic inconsistency and congestion. Flooding a query to every peer significantly diminishes the performance and effectiveness of the system. Hence, the new method namely SPIS with Query Filtering is proposed. Here, the query is filtered based on the file availability in the forwarding super-peer for reducing the number of duplication query which reduces the query processing time. Hence, the performance of the P2P networks can be improved and thereby reduces traffic.
An efficient scheme for two-link failure protection/restoration in WDM mesh networks
Authors: Ruan Lu , Xiao Nan
Published: December 2019

In this paper, we present a new hybrid protection and restoration scheme to handle two-link failure in WDM mesh networks. Some existing schemes for handling two-link failure use two backup paths to protect each demand or each link. Others reprovision backup paths for affected demands after the first link failure. Our hybrid scheme is more capacity efficient than previous schemes while being able to protect most of the demands upon two-link failure. The protection component of our hybrid scheme reserves backup capacity intelligently to ensure the majority of the affected demands can be restored using pre-planned backup paths upon two-link failure. For the rest of the affected demands, the restoration component of our hybrid scheme dynamically finds new backup paths to quickly restore them. The capacity efficiency and protection/restoration capability of our hybrid scheme are demonstrated through numerical results.
Human Growth Hormone Increases SMN Expression and Survival in Severe Spinal Muscular Atrophy Mouse Model
Authors: MacKenzie Duncan , Shamim Fahad , Mongeon Kevin , Trivedi Ankur , MacKenzie Alex , Farooq Faraz
Published: December 2019

Background: Autosomal recessive spinal muscle atrophy (SMA) is characterized by the loss of α motor neurons resulting in progressive muscle loss and respiratory failure. SMA is one of the most common inherited causes of infant death with a carrier frequency of 1 in 50 and a calculated prevalence of about 1 in 11,000 live births in the US. The low amount of functional survival motor neuron (SMN) protein due to mutations or deletion in the SMN1 gene causes SMA. Objective: A potential treatment strategy for SMA is to upregulate levels of SMN protein originating from the paralog SMN2 gene compensating in part for the absence of the SMN1 gene. Our group has previously shown that activation of the STAT5 pathway by lactation hormone prolactin (PRL) increased SMN levels, improved motor function and enhanced survival in a severe SMA mouse model. Given that human growth hormone (HGH) is also known to activate the STAT5 signalling pathway and is already used extensively in clinical settings, we thus elected to assess its impact on SMN levels. Methods and Results: Administration of HGH in NT2 cells activated STAT5 pathway which resulted into significant induction in SMN protein levels. Furthermore, systemic administration of HGH to transgenic SMA mice induced SMN protein levels in the brain and spinal cord samples. Critically, HGH treatment improved disease phenotype and increased survival in two severe SMA mouse models. Conclusions: Our results confirm earlier work suggesting STAT5 pathway activators as potential therapeutic compounds for the treatment of SMA and identify HGH as one such promising agent.
Prolonged Ambulation in Duchenne Patients with a Mutation Amenable to Exon 44 Skipping
Authors: van den Bergen J.C. , Ginjaar H.B. , Niks E.H. , Aartsma-Rus A. , Verschuuren J.J.G.M.
Published: December 2019

Duchenne muscular dystrophy has a severe disease course, though variability exists. Case reports suggest a milder disease course of patients amenable to exon 44 skipping. In this study, we analyzed this and show that age at wheelchair dependence in patients with a dystrophin deletion requiring exon 44 skipping is postponed compared to patients with a deletion skippable by exon 45, 51 and 53 (10.8 versus 9.8 years; P 0.020). This may be explained by more frequent spontaneous exon 44 skipping in patients with a deletion flanking exon 44. This finding has important implications for the development of future Duchenne trials.
Mass Spectrometry-Based Identification of Muscle-Associated and Muscle-Derived Proteomic Biomarkers of Dystrophinopathies
Authors: Dowling Paul , Holland Ashling , Ohlendieck Kay
Published: December 2019

The optimization of large-scale screening procedures of pathological specimens by genomic, proteomic and metabolic methods has drastically increased the bioanalytical capability for swiftly identifying novel biomarkers of inherited disorders, such as neuromuscular diseases. X-linked muscular dystrophy represents the most frequently inherited muscle disease and is characterized by primary abnormalities in the membrane cytoskeletal protein dystrophin. Mass spectrometry-based proteomics has been widely employed for the systematic analysis of dystrophin-deficient muscle tissues, using patient samples and animal models of dystrophinopathy. Both, gel-based methods and label-free mass spectrometric techniques have been applied in comparative analyses and established a large number of altered proteins that are associated with muscle contraction, energy metabolism, ion homeostasis, cellular signaling, the cytoskeleton, the extracellular matrix and the cellular stress response. Although these new indicators of muscular dystrophy have increased our general understanding of the molecular pathogenesis of dystrophinopathy, their application as new diagnostic or prognostic biomarkers would require the undesirable usage of invasive methodology. Hence, to reduce the need for diagnostic muscle biopsy procedures, more recent efforts have focused on the proteomic screening of suitable body fluids, such as plasma, serum or urine, for the identification of changed concentration levels of muscle-derived peptides, protein fragments or intact proteins. The occurrence of muscular dystrophy-related protein species in biofluids will be extremely helpful for the future development of cost-effective and non-invasive diagnostic procedures. Novel biomarker signatures of dystrophinopathies will be indispensible for the swift evaluation of innovative therapeutic approaches, such as exon skipping, codon-read-through or stem cell therapy.
Whole Exome Sequencing Reveals DYSF, FKTN, and ISPD Mutations in Congenital Muscular Dystrophy Without Brain or Eye Involvement
Authors: Ceyhan-Birsoy Ozge , Talim Beril , Swanson Lindsay C. , Karakaya Mert , Graff Michelle A. , Beggs Alan H. , Topaloglu Haluk
Published: December 2019

Background: Congenital muscular dystrophies (CMDs) are a genetically and clinically heterogeneous group of neuromuscular disorders. Several genes encoding extracellular matrix, nuclear envelope, sarcolemmal proteins and glycosylation enzymes have been implicated in CMDs. The large overlap of clinical presentations due to mutations in different genes poses a challenge for clinicians in determining disease etiology for each patient. Objective: We investigated the use of whole exome sequencing (WES) in identifying the genetic cause of disease in 5 CMD patients from 3 families who presented with highly similar clinical features, including early-onset rapidly progressive weakness without brain or eye abnormalities. Methods: Whole exome sequencing was performed on DNA from affected individuals. Potential functional impacts of mutations were investigated by immunostaining on available muscle biopsies. Results: Pathogenic mutations in 3 different genes, DYSF, FKTN, and ISPD were identified in each family. Mutation in DYSF led to absence of dysferlin protein in patient muscle. Mutations in ISPD led to impaired ISDP function, as demonstrated by deficiency of α-dystroglycan glycosylation in patient muscle. Conclusions: This study highlights the benefit of unbiased genomic approaches in molecular diagnosis of neuromuscular disorders with high clinical heterogeneity, such as the phenotypes observed in our patients. Our results suggest that dysferlin deficiency should be in the differential diagnosis of congenital and rapidly progressive muscular dystrophy, and therefore dysferlin antibody should be in the standard immunohistochemistry panel for muscle biopsies in cases with suspected CMD.
Dystroglycanopathies: About Numerous Genes Involved in Glycosylation of One Single Glycoprotein
Authors: Bouchet-Séraphin Céline , Vuillaumier-Barrot Sandrine , Seta Nathalie
Published: December 2019

Dystroglycanopathies are neuromuscular disorders due to abnormal glycosylation of dystroglycan which is a cell-surface glycoprotein that acts as a receptor for extracellular matrix proteins containing laminin-G domains. The reduced ability of abnormally glycosylated α−DG to bind laminin is associated with abnormal neuronal migration and muscular dystrophy. Clinical manifestations are extremely variable, and include a wide spectrum of phenotypic severity: some mutations are associated with adult-onset Limb-girdle muscular dystrophy and other mutations with a congenital onset, determining the more complex disorder Congenital Muscular Dystrophy which includes severe structural brain and eye anomalies such as Muscle-Eye-Brain Disease, Walker-Warburg Syndrome, and Fukuyama Congenital Muscular Dystrophy. So far, mutations in eighteen different genes have been identified in patients with dystroglycanopathies, all of them demonstrating autosomal recessive inheritance. Most genes code for glycosyltransferases (POMT1, POMT2, POMGNT1, LARGE, GTDC2, B4GAT1, B3GALNT2) although a minority does not (DPM1, DPM2, DPM3, DOLK, POMK, GMPPB). Others genes code for proteins of unknown function in the α−dystroglycan glycosylation (FKTN, FKRP, ISPD, and TMEM5) or α−dystroglycan itself, DAG1. The biochemical picture becomes a little bit more complete, but also more complex, with each new identified gene. In the majority of cases the identity of the defective gene cannot be predicted from the clinical phenotype. Considering the number of causative genes in dystroglycanopathies, targeted sequencing comprising genes of all glycosylation, whatever the type, would appear at present to be the best way of tackling molecular diagnosis.
Compliance to Care Guidelines for Duchenne Muscular Dystrophy
Authors: Landfeldt Erik , Lindgren Peter , Bell Christopher F. , Schmitt Claude , Guglieri Michela , Straub Volker , Lochmüller Hanns , Bushby Katharine
Published: December 2019

Background: International care guidelines for Duchenne muscular dystrophy (DMD) were published in 2010, but compliance in clinical practice is unknown. Objective: The objective of our study was to compare real-world DMD care in Germany, Italy, the UK, and the US with the clinical recommendations. Methods: DMD patients from Germany, Italy, the UK, and the US were identified through Translational Research in Europe – Assessment & Treatment of Neuromuscular Diseases (TREAT-NMD) registries and invited with a caregiver to complete a questionnaire with questions regarding DMD-related healthcare. Estimates of care were stratified by disease stage (early/late ambulatory/non-ambulatory) and compared against the care guidelines. Results: A total of 770 patients (173 German, 122 Italian, 191 UK, and 284 US) completed the questionnaire. Poor compliance to guidelines of routine follow-up by neuromuscular, cardiac, and respiratory specialists, physiotherapy, and access to medical devices and aids were observed in all countries. Less than 27% (209 of 770) of patients met all absolute recommendations, ranging from 9% (11 of 122) in Italy to 37% (70 of 191) in the UK, and from 49% (76 of 155) in the early ambulatory class to 16% (33 of 205) in the late non-ambulatory class. Conclusions: We show that the medical management of DMD varies substantially between Germany, Italy, the UK, and the US. Experience of real-world DMD care appears to be in poor agreement with the DMD clinical guidelines and increased compliance is urgently needed to improve treatment outcomes and enable patients to lead fulfilling, independent lives into adulthood.