Showing papers on "Transmission delay published in 2014"

Device-to-device communications in cellular networks

Abstract: Device-to-device communications enable two proximity users to transmit signal directly without going through the base station. It can increase network spectral efficiency and energy efficiency, reduce transmission delay, offload traffic for the BS, and alleviate congestion in the cellular core networks. However, many technical challenges need to be addressed for D2D communications to harvest the potential benefits, including device discovery and D2D session setup, D2D resource allocation to guarantee QoS, D2D MIMO transmission, as well as D2D-aided BS deployment in heterogeneous networks. In this article, the basic concepts of D2D communications are first introduced, and then existing fundamental works on D2D communications are discussed. In addition, some potential research topics and challenges are also identified.

NFC collision avoidance with controllable NFC transmission delay timing

Abstract: A first near field communication (NFC) circuit includes an antenna, a charging circuit, a transceiver circuit, and a transmission delay circuit. The antenna is configured to inductively couple to signals emitted by a second NFC circuit. The charging circuit is configured to output power provided by the inductive coupling through the antenna to the signals emitted by the second NFC circuit. The transceiver circuit is configured to be powered by the charging circuit to transmit data for receipt by the second NFC circuit. The transmission delay circuit is configured to be powered by the charging circuit and control the transceiver circuit to delay transmission of the data until expiration of a defined delay time after the transceiver circuit has become sufficiently powered on to operate to transmit the data. Related accessories for user equipment, user equipment, and methods are disclosed.

User-plane congestion management

Abstract: Methods, apparatuses and systems for user-plane congestion management are provided. Among these method, apparatuses and systems is a method, implementable by a base station (and/or a serving gateway), for mitigating user plane congestion. The method may include sending a congestion indication to a core network; receiving a general packet radio system (GPRS) tunneling protocol (GTP) packet including an first internet protocol (IP) packet associated with a first flow within a bearer; obtaining, from a header of the GTP packet, an indicator indicative of a priority of the IP packet, wherein the indicator was inserted into the header of the GTP packet by the core network responsive to the congestion indication; and dropping any of the GTP packet and the first IP packet on condition that a priority of a second IP packet associated with second flow within the bearer takes precedence over the priority of the first IP packet.

Pinning synchronization of hybrid-coupled directed delayed dynamical network via intermittent control

Abstract: This paper concerns the problem of exponential synchronization for a class of general delayed dynamical networks with hybrid coupling via pinning periodically intermittent control. Both the internal delay and coupling delay are taken into account in the network model. Meanwhile, the transmission delay and self-feedback delay are involved in the delayed coupling term. By establishing a new differential inequality, several simple and useful exponential synchronization criteria are derived analytically. It is shown that the controlled synchronization state can vary in comparison with the conventional synchronized solution, and the degree of the node and the inner delayed coupling matrix play important roles in the controlled synchronization state. By choosing different inner delayed coupling matrices and the degrees of the node, different controlled synchronization states can be obtained. Furthermore, the detail pinning schemes deciding what nodes should be chosen as pinned candidates and how many nodes are needed to be pinned for a fixed coupling strength are provided. The simple procedures illuminating how to design suitable intermittent controllers in real application are also given. Numerical simulations, including an undirected scale-free network and a directed small-world network, are finally presented to demonstrate the effectiveness of the theoretical results.

Interleaving advertising packets for improved detectability and security

Abstract: Methods, systems and devices for broadcasting messages of different packet formats in interleaving fashions, wherein a transmitter may broadcast a first packet in a first format configured to be well-suited for a first software implementation of a receiver and broadcast a second packet in a second format that is associated with a second software implementation (e.g., firmware, application, etc.). The receiver may receive and process the first packet to detect information that indicates the presence of messages of the second packet type, adjust the receiver (i.e., change a behavior of the second software implementation) in response to detecting information, receive and process the second packet via the second software implementation, and perform an action based on the processed second packet. In some embodiments, the first and/or second messages may include portions of data that may be combined by the receiver.

16.1 A 340mV-to-0.9V 20.2Tb/s source-synchronous hybrid packet/circuit-switched 16×16 network-on-chip in 22nm tri-gate CMOS

Abstract: Energy-efficient networks-on-chip (NoCs) are key enablers for exa-scale computation by shifting power budget from communication toward computation. As core counts scale into the 100s, on-chip interconnect fabrics must support increasing heterogeneity and voltage/clock domains. Synchronous NoCs require either a single clock distributed globally or clock-crossing data FIFOs between clock domains [1]. A global clock requires costly full-chip margining and significant power and area for clock distribution, while synchronizing data FIFOs add power, performance, and area overhead per clock crossing. Source-synchronous NoCs mitigate these penalties by forwarding a local clock along with each packet, but still suffer from high data storage power due to packet switching. Circuit switching removes intra-route data storage, but suffers from low network utilization due to serialized channel setup and data transfer [2]. Hybrid packet/circuit switching parallelizes these operations for higher network utilization. A 16×16 mesh, 112b data, 256 voltage/clock domain NoC with source-synchronous operation, hybrid packet/circuit-switched flow control, and ultra-low-voltage optimizations is fabricated in 22nm tri-gate CMOS [3] to enable: i) 20.2Tb/s total throughput at 0.9V, 25°C, ii) a 2.7× increase in bisection bandwidth to 2.8Tb/s and 93% reduction in circuit-switched latency at 407ps/hop through source-synchronous operation, iii) a 62% latency improvement and 55% increase in energy efficiency to 7.0Tb/s/W through circuit switching, iv) a peak energy efficiency of 18.3Tb/s/W for near-threshold operation at 430mV, 25°C, and v) ultra-low-voltage operation down to 340mV with router power scaling to 363μW.

Why are you so slow? – Misattribution of transmission delay to attributes of the conversation partner at the far-end

Abstract: This study addresses the question of how transmission delay affects user perception during speech communication over telephone systems. It aims to show that the occurrence of pure delay should not be neglected when planning a telephone or conferencing system even if no impact on the perceived quality of the call can be found. It is, for instance, known that, the communication surface structure changes dramatically when transmission delay is inserted by the communication system. Furthermore, studies suggest a change in the perception of the interlocutor at the far-end. This paper describes two experiments that assess the misattribution of the technical impairment delay to personality and behavior-related attributes of the conversation partners. The first experiment shows that interlocutors are perceived as being less attentive when conversing in a three-party setting with symmetrical and asymmetrical delay conditions. In the second experiment, the misattribution is considered in more detail looking at ascribed personality attributes in two-party interaction under transmission delay. For both experiments, comparing the conversation surface structure of delayed to non-delayed calls helped to understand the found outcomes.

Tracing network packets by a cluster of network controllers

Abstract: A process is performed by logical controller 2205 which is at the top of the hierarchy of a controller cluster and which receives trace requests from a user and generates trace packets. A command is received (1) to insert a test packet marked for a trace operation with specified source and destination addresses on a set of logical forwarding elements into the physical network implementing the logical forwarding elements. Next, a packet is generated with the specified source and destination addresses. A tracing operation identifier may uniquely identify the particular trace operation issued by the logical controller. The generated packet is then sent (2) to a physical controller 2210 that manages the edge MFE (managed forwarding element) associated with the source of the packet. The physical controller 2210 identifies MFE 2090 into which to inject the packet. Physical controller 2010 may modify register bits for the packet at the MFE in order to simulate the receiving of the packet through the appropriate physical port of the MFE even though it was received from the physical controller. Processing operations 2240 and 2245 result in the MFE 2290 sending (4), (6) observations to the physical controller 2210. A set of analyses of observation messages is next received (5), (7), (9), (12), (14) from a set of physical controllers 2210, 2215 which manage the MFEs 2090, 2092 through which the trace packet passes (10). Finally, a report is generated based on the received analyses and sent (15) to the requesting user.

Packet time stamp processing methods, systems, and apparatus

Abstract: Methods, systems, and apparatus for monitoring network devices and identifying packet anomalies are described herein. Anomalies may be identified by receiving packets from a network device at a network monitor, each packet having a first time stamp added by the network device, adding a second time stamp to the packets by the network monitor, comparing the first time stamp and the second time stamp of each packet, and identifying an anomaly associated with a packet in response to a difference metric generated based on the first and second time stamps exceeding a threshold.

A connectivity-aware intersection-based routing in VANETs

Abstract: Vehicular ad hoc networks (VANETs) are going to be an important communication infrastructure in our moving life. The design of routing protocols in VANETs is a significant and necessary issue for supporting VANET-based applications. However, due to high mobility, frequent link disconnection, and uneven distribution of vehicles, it becomes quite challenging to establish a robust route for delivering packets. This paper presents a connectivity-aware intersection-based routing (CAIR) protocol to address these problems by selecting an optimal route with higher probability of connectivity and lower experienced delay; then, geographical forwarding based on position prediction is used to transfer packets between any two intersections along the route. Simulation results show that the proposed protocol outperforms existing routing protocols in terms of data delivery ratio and average transmission delay in typical urban scenarios.

A Scalable CSMA and Self-Organizing TDMA MAC for IEEE 802.11 p/1609.x in VANETs

Abstract: vehicular ad hoc networks (VANETs) have been a key topic for research community and industry alike. The wireless access in vehicular environment standard employs the IEEE 802.11p/1609.4 for the Medium Access Control (MAC) layer implementation for VANETs. However, the carrier sense multiple access (CSMA) based mechanism cannot provide reliable broadcast services, and the multi-channel operation defined in IEEE 1609.4 divides the available access time into fixed alternating control channel intervals (CCH) and service channel (SCH) intervals, which may lead to the low utilization of the scarce resources. In this paper, a novel multichannel MAC protocol called CS-TDMA considering the channel access scheduling and channel switching concurrently is proposed. The protocol combines CSMA with the time division multiple access (TDMA) to improve the broadcast performance in VANETs. Meanwhile, the dwelling ratio between CCH and SCH changes dynamically according to the traffic density, resulting in the improvement of resource utilization efficiency. Simulation results are presented to verify the effectiveness of our mechanism and comparisons are made with three existing MAC protocols, IEEE MAC, SOFT MAC and VeMAC. The simulation results demonstrate the superiority of CS-TDMA in the reduction of transmission delay and packet collision rate and improvement of network throughput.

Method and apparatus for identifying network transmission congestion

Abstract: Embodiments of the present invention provide a method and apparatus for identifying a network transmission congestion. The method comprises: acquiring actual packet loss ratios and actual sending rates on N sampling time points and an actual packet loss ratio on an (N+1) th sampling time point; acquiring, according to the actual packet loss ratios and the actual sending rates on the N sampling time points and the actual packet loss ratio on the (N+1) th sampling time point, a detection value used for determining whether a transmission congestion occurs on a network; comparing the detection value with a preset decision value; and if the detection value is greater than or equal to the decision value, identifying that the network is in the transmission congestion state. In the embodiment, actual packet loss ratios and actual sending rates on multiple sampling time points are acquired by means of sampling, a detection value used for determining whether a network is in a transmission congestion is obtained by means of calculation, and it is determined whether the network is in the transmission congestion state according to the detection value, and therefore, the accuracy of the identification result is improved.

Method and apparatus for time stretching to hide data packet pre-buffering delays

Abstract: A special rendering mode for the first few seconds of play out of multimedia data minimizes the delay caused by pre-buffering of data packets in multimedia streaming applications. Instead of pre-buffering all incoming data packets until a certain threshold is reached, the streaming application starts playing out some of the data packets immediately after the arrival of the first data packet. Immediate play out of the first data packet, for example, results in minimum delay between channel selection and perception, thereby allowing a user to quickly scan through all available channels to quickly get a notion of the content. The immediate play out is done at a reduced speed.

Optical Packet and Circuit Integrated Networks and Software Defined Networking Extension

Abstract: An optical packet and circuit integrated network (OPCInet) provides both high-speed, inexpensive services and deterministic-delay, low-data-loss services according to the users’ usage scenarios, from the viewpoint of end users. From the viewpoint of network service providers, this network provides large switching capacity with low energy consumption, high flexibility, and efficient resource utilization with a simple control mechanism. This paper presents the recent progress made in the development of OPCInet and its extension to software-defined networking (SDN). We have developed OPCI nodes, which are capable of layer 3 switching from/to an Ethernet frame to/from an optical packet in the optical packet edge part and a burst-tolerant optical amplifier and an optical buffer with optical fiber delays in 100 Gbps optical packet switching part. The OPCI node achieves a packet error rate less than $10^{-4}$ and is used as a node in a lab-network that has access to the Internet. A distributed automatic control works in a control plane for the circuit switching part and in a moving boundary control between optical packet resources and circuit resources. Our optical system for packet and circuit switching works with a centralized control mechanism as well as a distributed control mechanism. We have shown a packet-based SDN system that configures mapping between IP addresses and OPCI node identifiers and switching tables according to the requests from multiple service providers via a web interface.

Non-Stationary Resource Allocation Policies for Delay-Constrained Video Streaming: Application to Video over Internet-of-Things-Enabled Networks

Abstract: Due to the high bandwidth requirements and stringent delay constraints of multi-user wireless video transmission applications, ensuring that all video senders have sufficient transmission opportunities to use before their delay deadlines expire is a longstanding research problem. We propose a novel solution that addresses this problem without assuming detailed packet-level knowledge, which is unavailable at resource allocation time (i.e. prior to the actual compression and transmission). Instead, we translate the transmission delay deadlines of each sender's video packets into a monotonically-decreasing weight distribution within the considered time horizon. Higher weights are assigned to the slots that have higher probability for deadline-abiding delivery. Given the sets of weights of the senders' video streams, we propose the low-complexity Delay-Aware Resource Allocation (DARA) approach to compute the optimal slot allocation policy that maximizes the deadline-abiding delivery of all senders. A unique characteristic of the DARA approach is that it yields a non-stationary slot allocation policy that depends on the allocation of previous slots. This is in contrast with all existing slot allocation policies such as round-robin or rate-adaptive round-robin policies, which are stationary because the allocation of the current slot does not depend on the allocation of previous slots. We prove that the DARA approach is optimal for weight distributions that are exponentially decreasing in time. We further implement our framework for real-time video streaming in wireless personal area networks that are gaining significant traction within the new Internet-of-Things (IoT) paradigm. For multiple surveillance videos encoded with H.264/AVC and streamed via the 6tisch framework that simulates the IoT-oriented IEEE 802.15.4e TSCH medium access control, our solution is shown to be the only one that ensures all video bitstreams are delivered with acceptable quality in a deadline-abiding manner.

2L-MAC: A MAC protocol with two-layer interference mitigation in wireless body area networks for medical applications

Abstract: This paper investigates the issue of interference mitigation in wireless body area networks (BANs). Although several approaches have been proposed in BAN standard IEEE 802.15.6, they increase transmission latency or energy cost, and do not mitigate interference effectively. In order to avoid both intra- and inter-BAN interference, we present a MAC protocol with two-layer interference mitigation (2L-MAC) for BANs. Considering the QoS requirements of BANs, the proposed protocol not only avoids packet collisions but also reduces transmission delay and energy consumption in sensors. Moreover, channel switching is triggered whenever a BAN needs to acquire more bandwidth. Simulation results show that our protocol outperforms other protocols in terms of delivery rate, latency and energy saving.

System and method for software defined routing of traffic within and between autonomous systems with enhanced flow routing, scalability and security

Abstract: An autonomous network and a corresponding routing method include determining routing paths by a controller, and providing the determined routing paths to a data packet processor located remotely from the controller. The data packet processor routes outgoing data packets, based on information from the controller, through a plurality of switches remotely from the data packet processor. Each switch includes a plurality of network interfaces. For an outgoing data packet, the data packet processor determines a network interface over which to transmit the data packet, and adds an indication of the determined network interface in a header of the data packet. The data packet processor forwards the modified data packet to the switch including the determined network interface. The switch identifies the network interface based on the indication, and transmits the outgoing data packet over the identified network interface.

A QoS-Oriented Distributed Routing Protocol for Hybrid Wireless Networks

Abstract: As wireless communication gains popularity, significant research has been devoted to supporting real-time transmission with stringent Quality of Service (QoS) requirements for wireless applications. At the same time, a wireless hybrid network that integrates a mobile wireless ad hoc network (MANET) and a wireless infrastructure network has been proven to be a better alternative for the next generation wireless networks. By directly adopting resource reservation-based QoS routing for MANETs, hybrids networks inherit invalid reservation and race condition problems in MANETs. How to guarantee the QoS in hybrid networks remains an open problem. In this paper, we propose a QoS-Oriented Distributed routing protocol (QOD) to enhance the QoS support capability of hybrid networks. Taking advantage of fewer transmission hops and anycast transmission features of the hybrid networks, QOD transforms the packet routing problem to a resource scheduling problem. QOD incorporates five algorithms: 1) a QoS-guaranteed neighbor selection algorithm to meet the transmission delay requirement, 2) a distributed packet scheduling algorithm to further reduce transmission delay, 3) a mobility-based segment resizing algorithm that adaptively adjusts segment size according to node mobility in order to reduce transmission time, 4) a traffic redundant elimination algorithm to increase the transmission throughput, and 5) a data redundancy elimination-based transmission algorithm to eliminate the redundant data to further improve the transmission QoS. Analytical and simulation results based on the random way-point model and the real human mobility model show that QOD can provide high QoS performance in terms of overhead, transmission delay, mobility-resilience, and scalability.

Optimal Load Balancing and Energy Cost Management for Internet Data Centers in Deregulated Electricity Markets

Abstract: Along with the rapid increasing energy consumption, the energy cost of Internet data centers (IDCs) has been skyrocketing. A novel scheme of geographical load balancing was proposed to reduce electricity bills for service providers. However, one important challenge faced by service providers has not been considered properly. In service systems, the service delay faced by consumers includes the queuing delay and the transmission delay. While existing work only consider the queuing delay, the transmission delay introduced by geographical load balancing has been overlooked. It is one of the most important factors affecting the quality of service for real-time service systems. In this paper, we take the transmission delay into our design consideration and formulate a mixed-integer nonlinear programming (MINLP) problem with coupled constraint to achieve the optimal load balancing and energy cost management for IDCs while meeting the service-level agreements (SLA) of consumers. A novel heuristic based branch and bound with feedback (HBBF) algorithm is proposed to decouple the MINLP problem with coupled constraint efficiently. Extensive performance evaluations based on real electricity price data and site-to-site transmission delay data demonstrate the effectiveness of our proposed algorithm.

Community based effective social video contents placement in cloud centric CDN network

Abstract: The increasing popularity of online social networks (OSNs) has been transforming the dissemination pattern of social video contents. Considering the unique features of social videos, e.g., huge volume, long-tailed, and short length, how to utilize the information propagation pattern to improve the efficiency of content distribution for social videos attracts more and more attention. In this paper, we first conduct a large scale measurement to explore the social video viewing behavior under the community classification. Based on the measurement, we investigate the community driven sharing video distribution problem under the cloud-centric content delivery network (CDN) architecture. In particular, we formulate it as a constrained optimization problem with the objective to minimize the operational cost. The constraint is the averaged transmission delay. Following that, we propose a dynamic algorithm to seek the optimal solution. Our trace-driven experiments further demonstrate our algorithm can make a better tradeoff between monetary cost and QoS, and outperforms the traditional method with less operational cost while satisfying the QoS requirement.

Spectrum-Map-Empowered Opportunistic Routing for Cognitive Radio Ad Hoc Networks

Abstract: Cognitive radio (CR) has emerged as a key technology for enhancing spectrum efficiency by creating opportunistic transmission links. Supporting the routing function on top of opportunistic links is a must for transporting packets in a CR ad hoc network (CRAHN) consisting of cooperative relay multi-radio systems. However, there lacks a thorough understanding of these highly dynamic opportunistic links and a reliable end-to-end transportation mechanism over the network. Aspiring to meet this need, with innovative establishment of the spectrum map from local sensing information, we first provide a mathematical analysis to deal with transmission delay over such opportunistic links. Benefitting from the theoretical derivations, we then propose spectrum-map-empowered opportunistic routing protocols for regular and large-scale CRAHNs with wireless fading channels, employing a cooperative networking scheme to enable multipath transmissions. Simulations confirm that our solutions enjoy significant reduction of end-to-end delay and achieve dependable communications for CRAHNs, without commonly needed feedback information from nodes in a CRAHN to significantly save the communication overhead at the same time.

Systems and methods for software defined networking service function chaining

Abstract: Systems and methods are disclosed for steering packet traffic through an online network. One method includes receiving, at a switch of a network, a packet of data; classifying, by the switch, the packet to a service function chain based on fields of a packet header of the packet, the service function chain including a set of service functions to be performed on the packet; setting, by the switch, fields of the packet header to identify the service function chain classified; and transmitting, by the switch over the network, the packet to a service function device that performs a service function on the packet, the service function being in the set of service functions.

Dynamic rate adaptation for improved throughput and delay in wireless network coded broadcast

Abstract: In this paper, we provide theoretical and simulation-based study of the delivery delay performance of a number of existing throughput-optimal coding schemes and use the results to design a new dynamic rate adaptation scheme that achieves improved overall throughput-delay performance. Under a baseline rate control scheme, the receivers' delay performance is examined. Based on their Markov states, the knowledge difference between the sender and receiver, three distinct methods for packet delivery are identified: zero state, leader state, and coefficient-based delivery. We provide analyses of each of these and show that, in many cases, zero state delivery alone presents a tractable approximation of the expected packet delivery behavior. Interestingly, while coefficient-based delivery has so far been treated as a secondary effect in the literature, we find that the choice of coefficients is extremely important in determining the delay, and a well-chosen encoding scheme can, in fact, contribute a significant improvement to the delivery delay. Based on our delivery delay model, we develop a dynamic rate adaptation scheme that uses performance prediction models to determine the sender transmission rate. Surprisingly, taking this approach leads us to the simple conclusion that the sender should regulate its addition rate based on the total number of undelivered packets stored at the receivers. We show that despite its simplicity, our proposed dynamic rate adaptation scheme results in noticeably improved throughput-delay performance over existing schemes in the literature.

BATS: Network coding in action

Abstract: BATS code is a low-complexity random linear network coding scheme that can achieve asymptotic bandwidth optimality for many types of networks with packet loss. In this paper, we propose a BATS code based network protocol and evaluate the performance by real-device experiments. Our results demonstrate significant ready-to-implement gain of network coding over forwarding in multi-hop network transmission with packet loss. We also propose an improved protocol to handle the practical issues observed in the experiments.

Path selection using handover in mobile networks with cloud-enabled small cells

Abstract: To overcome latency constrain of common mobile cloud computing, computing capabilities can be integrated into a base station in mobile networks This exploitation of convergence of mobile networks and cloud computing enables to take advantage of proximity between a user equipment (UE) and its serving station to lower latency and to avoid backhaul overloading due to cloud computing services This concept of cloud-enabled small cells is known as small cell cloud (SCC) In this paper, we propose algorithm for selection of path between the UE and the cell, which performs computing for this particular UE As a path selection metrics we consider transmission delay and energy consumed for transmission of offloaded data The path selection considering both metrics is formulated as Markov Decision Process Comparing to a conventional delivery of data to the computing small cells, the proposed algorithm enables to reduce the delay by 9% and to increase users' satisfaction with experienced delay by 65%

Systems and methods to cache packet steering decisions for a cluster of load balancers

Abstract: The present disclosure is directed towards methods and systems for caching packet steering sessions for steering data packets between intermediary devices of a cluster of intermediary devices intermediary to a client and a plurality of servers. A first intermediary device receives a first data packet and determines, from a hash of a tuple of the first packet, a second intermediary device to which to steer the first packet. The first device stores, to a session for storing packet steering information, the identity of the second device and the tuple. The first device receives a second packet having a corresponding tuple that matches the tuple of the first packet and determines, based on a lookup for the session using the tuple of the second packet, that the second device is the intermediary device to which to steer the second packet. The first device steers the second packet to the second device.

Method and Apparatus for Time Limited Messages in Packet Communications

Abstract: The present disclosure includes systems and methods for direct packet communications and store and forward packet communications including packets which have attributes which determine the lifetime of the packet contents and these lifetimes are optionally a function of the recipient. Example methods are given featuring the transmission of packets with limited lifetime, the storing and retransmission of packets to one or more recipients and confirmation of deletion of packet contents. It is also shown that cryptography may be employed to ensure that timed presentation of packet contents to recipients takes place and is authenticated by the sender.

Low-cost flow matching in software defined networks without tcams

Abstract: Various exemplary embodiments relate to a method for processing data packets by a first-hop switch in a data network, including: receiving a first data packet associated with a flow; determining whether the flow associated with the first data packet is found in a flow table in the first-hop switch; modifying the first data packet by replacing a packet header field with flow definition information; and transmitting the modified first data packet based upon the flow definition information.