Showing papers on "Circuit switching published in 2013"

Integrating microsecond circuit switching into the data center

Abstract: Recent proposals have employed optical circuit switching (OCS) to reduce the cost of data center networks. However, the relatively slow switching times (10--100 ms) assumed by these approaches, and the accompanying latencies of their control planes, has limited its use to only the largest data center networks with highly aggregated and constrained workloads. As faster switch technologies become available, designing a control plane capable of supporting them becomes a key challenge.In this paper, we design and implement an OCS prototype capable of switching in 11.5 us, and we use this prototype to expose a set of challenges that arise when supporting switching at microsecond time scales. In response, we propose a microsecond-latency control plane based on a circuit scheduling approach we call Traffic Matrix Scheduling (TMS) that proactively communicates circuit assignments to communicating entities so that circuit bandwidth can be used efficiently.

Wireless charging circuit, wireless charging system and semiconductor device

Abstract: To satisfy the NFC communication standard in wireless charging with a shared antenna, used for NFC communication. A power supply unit includes a voltage step-down circuit 331 , a charge control circuit 332 , and a communication controller power supply circuit 333 . The voltage step-down circuit includes a switching regulator 200 , and a selection circuit 206 and 208 which can select an output path PT 1 of the switching regulator and a bypass path PT 2 of the switching regulator. The voltage step-down circuit includes a selection control circuit 207 . The selection control circuit supplies voltage to the communication controller power supply circuit via the bypass path at the time of activating the communication controller. Since the output voltage of the series regulator stabilizes in a shorter time than the switching regulator, it becomes possible to keep the time from when RF power rises to when initial communication becomes possible, within standards.

Experimental demonstration of an OpenFlow based software-defined optical network employing packet, fixed and flexible DWDM grid technologies on an international multi-domain testbed.

Abstract: Software defined networking (SDN) and flexible grid optical transport technology are two key technologies that allow network operators to customize their infrastructure based on application requirements and therefore minimizing the extra capital and operational costs required for hosting new applications. In this paper, for the first time we report on design, implementation & demonstration of a novel OpenFlow based SDN unified control plane allowing seamless operation across heterogeneous state-of-the-art optical and packet transport domains. We verify and experimentally evaluate OpenFlow protocol extensions for flexible DWDM grid transport technology along with its integration with fixed DWDM grid and layer-2 packet switching.

All-optical packet/circuit switching-based data center network for enhanced scalability, latency, and throughput

Abstract: Applications running inside data centers are enabled through the cooperation of thousands of servers arranged in racks and interconnected together through the data center network. Current DCN architectures based on electronic devices are neither scalable to face the massive growth of DCs, nor flexible enough to efficiently and cost-effectively support highly dynamic application traffic profiles. The FP7 European Project LIGHTNESS foresees extending the capabilities of today's electrical DCNs throPugh the introduction of optical packet switching and optical circuit switching paradigms, realizing together an advanced and highly scalable DCN architecture for ultra-high-bandwidth and low-latency server-to-server interconnection. This article reviews the current DC and high-performance computing (HPC) outlooks, followed by an analysis of the main requirements for future DCs and HPC platforms. As the key contribution of the article, the LIGHTNESS DCN solution is presented, deeply elaborating on the envisioned DCN data plane technologies, as well as on the unified SDN-enabled control plane architectural solution that will empower OPS and OCS transmission technologies with superior flexibility, manageability, and customizability.

Photonic Network-on-Chip Design

Abstract: Introduction.- Photonic Interconnects.- Silicon Photonics.- Photonic Simulation and Design Space.- Photonic Network Architectures I: Circuit Switching.- Photonic Network Architectures II: Wavelength Arbitration and Routing.- Photonic Network Architectures III: Advanced Photonic Architectures.- Conclusions.

Field Trial of an OpenFlow-Based Unified Control Plane for Multilayer Multigranularity Optical Switching Networks

Abstract: Software defined networking and OpenFlow, which allow operators to control the network using software running on a network operating system within an external controller, provide the maximum flexibility for the operator to control a network, and match the carrier's preferences given its centralized architecture, simplicity, and manageability. In this paper, we report a field trial of an OpenFlow-based unified control plane (UCP) for multilayer multigranularity optical switching networks, verifying its overall feasibility and efficiency, and quantitatively evaluating the latencies for end-to-end path creation and restoration. To the best of our knowledge, the field trial of an OpenFlow-based UCP for optical networks is a world first.

A Multiport Microsecond Optical Circuit Switch for Data Center Networking

Abstract: We experimentally evaluate the network-level switching time of a functional 23-host prototype hybrid optical circuit-switched/electrical packet-switched network for datacenters called Mordia (Microsecond Optical Research Datacenter Interconnect Architecture). This hybrid network uses a standard electrical packet switch and an optical circuit-switched architecture based on a wavelength-selective switch that has a measured mean port-to-port network reconfiguration time of 11.5 $\mu{\rm s}$ including the signal acquisition by the network interface card. Using multiple parallel rings, we show that this architecture can scale to support the large bisection bandwidth required for future datacenters.

Design and Evaluation of a Flexible-Bandwidth OFDM-Based Intra-Data Center Interconnect

Abstract: Data center networks are facing growing challenges to deliver higher bandwidth efficiency, lower latency, better flexibility, and lower cost. Various optical interconnect schemes have been proposed to take advantage of the high bandwidth capacity and low power consumption offered by optical switching. However, these schemes cannot offer flexible bandwidth sharing due to the large granularity in optical circuit switching, and they require costly optical components. In this paper, we introduce a novel data center network architecture based on cyclic arrayed waveguide grating device and multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing technology with parallel signal detection (PSD). This architecture offers flexible bandwidth resource sharing at fine granularity. Other features include high-speed switching, low and uniform latency, and the ability to change the data rates dynamically. By eliminating costly optical components and keeping the core optical router passive and static, the power consumption, hardware cost, and operation cost are reduced. The fine granularity bandwidth sharing and MIMO switching through PSD are verified experimentally. We also propose and evaluate efficient subcarrier allocation schemes to achieve high bandwidth utilization. Finally, we present the implementation of an efficient scheduler for the bandwidth allocation of the proposed scheme.

Methods and apparatus for enhancing circuit-switched call fallback (csfb) service for a shared network node

Abstract: Methods and apparatus enhance a circuit-switched call fallback (CSFB) service for a user equipment (UE) currently connected to a source cell in a serving radio access technology (RAT) communications network. Multiple different mobile network operators share a target CSFB cell selected for CSFB from one or more circuit-switched capable cells that supports circuit-switched services. Each mobile network operator is associated with a corresponding mobile network identifier. The UE transmits a first message requesting a CSFB service to a source cell radio network node serving the source cell. The source node, in response to the first message, sends a second message to the UE including preferred mobile network identifier information and a target CSFB cell identifier. The UE transmits a third message to a target cell node serving the target CSFB cell to trigger the establishment of a circuit-switched call connection for the UE in the target CSFB cell. The target cell radio network node receives the third message, which includes preferred mobile network information to permit the target node to direct the third message to a core network node operated by one of the mobile network operators identifiable based on the preferred mobile network information. That core network node then initiates the requested CSFB service for the UE. Based on the preferred mobile network identifier information, the UE determines whether a location area update procedure must be performed in the target CSFB cell, and if so, transmits a fourth message to trigger the location area update procedure prior to triggering the establishment of a circuit-switched call connection.

A 10 µs hybrid optical-circuit/electrical-packet network for datacenters

Abstract: We built and evaluated a hybrid electrical-packet/optical-circuit network for datacenters using a 10 μs optical circuit switch using wavelength-selective switches based on binary MEMs. This network has the potential to support large-scale, dynamic datacenter workloads.

Complexity analysis and algorithm design for advance bandwidth scheduling in dedicated networks

Abstract: An increasing number of high-performance networks provision dedicated channels through circuit switching or MPLS/GMPLS techniques to support large data transfer. The link bandwidths in such networks are typically shared by multiple users through advance reservation, resulting in varying bandwidth availability in future time. Developing efficient scheduling algorithms for advance bandwidth reservation has become a critical task to improve the utilization of network resources and meet the transport requirements of application users. We consider an exhaustive combination of different path and bandwidth constraints and formulate four types of advance bandwidth scheduling problems, with the same objective to minimize the data transfer end time for a given transfer request with a prespecified data size: 1) fixed path with fixed bandwidth (FPFB); 2) fixed path with variable bandwidth (FPVB); 3) variable path with fixed bandwidth (VPFB); and 4) variable path with variable bandwidth (VPVB). For VPFB and VPVB, we further consider two subcases where the path switching delay is negligible or nonnegligible. We propose an optimal algorithm for each of these scheduling problems except for FPVB and VPVB with nonnegligible path switching delay, which are proven to be NP-complete and nonapproximable, and then tackled by heuristics. The performance superiority of these heuristics is verified by extensive experimental results in a large set of simulated networks in comparison to optimal and greedy strategies.

Integrating microsecond circuit switching into the data center

Abstract: Recent proposals have employed optical circuit switching (OCS) to reduce the cost of data center networks. However, the relatively slow switching times (10--100 ms) assumed by these approaches, and...

Delaying network reselection following performance of a circuit switched fallback procedure in a call failure scenario

Abstract: A method for delaying network reselection by a wireless communication device following a call failure is provided The method can include determining an initiation of a voice call while connected to a first network The method can further include participating in a circuit switched fallback (CSFB) procedure to transition from the first network to a second network in response to initiation of the voice call The method can additionally include determining an occurrence of a call failure of the voice call The method can also include, responsive to the call failure, barring reselection to the first network for a threshold barring period

Rethinking IP core networks

Abstract: The Internet core today is completely based on IP routers. Circuits are only used to provide static point-to-point optical links between routers. As others have recognized, current practice makes it hard to take advantage of very high-speed, low-power optical circuit switches in the core. Despite many proposals to mix packet switching with dynamic circuit switching, none have taken hold. In these times of rapidly increasing traffic, and rapidly decreasing profits for ISPs, it is time to rethink how backbones are built. In this paper, we propose to replace the largest backbone routers with much cheaper hybrid packet-optical switches in a fully meshed IP core. We take advantage of new control planes for software-defined networks to control the packet and circuit networks from a single vantage point. To demonstrate the enormous potential cost savings, we present a detailed analysis of the capital expenditure and show how our approach offers 60% cost savings for typical backbone operators.

A 65nm 39GOPS/W 24-core processor with 11Tb/s/W packet-controlled circuit-switched double-layer network-on-chip and heterogeneous execution array

Abstract: With the increasing complexity and variety of applications, programmable multi-core processors are drawing attention due to their high flexibility and low implementation cost, yet their performance and energy efficiency still cannot fulfill the demands of many compute-intensive applications. This paper describes a high-performance energy-efficient 24-core processor for multi-media and communication applications, with the following key features: (1) a packet-controlled circuit-switched double-layer network-on-chip (NoC) which provides 11Tb/s/W energy efficiency with 435Gb/s bisection-bandwidth; (2) a cluster-shared NoC-connected heterogeneous reconfigurable execution array, which can improve the performance of frequently used computations in multimedia and communication applications by over 6×; (3) memory hierarchy improvements, including a multi-page foreground and background register file, and memory splitting and sharing. The processor, implemented in TSMC 65nm CMOS LP and occupying 18.8mm2 (Fig. 3.6.7) operates at 850MHz at 1.2V, with 523mW power dissipation and 39GOPS/W (26pJ/operation) energy efficiency, which is 1.75× better than our former 16-core processor [3].

System and method for enabling communications over a number of packet networks

Abstract: The disclosed embodiments include a computer implemented method for routing data packets. In one embodiment, the method includes storing network usage information of a packet network managed by a communications carrier including network usage information associated with communications by subscribers of other communications carrier that communicate data packets over the packet network, the network usage information distinguishing between data packets associated with a first service and data packets associated with a second service; determining pricing information for communicating the data packets via a plurality of networks, wherein each network is associated with a different communications carrier; and selecting one of the plurality of networks for routing the data packets based on cost, wherein the cost includes a first cost for communicating the data packets that are associated with the first service and a second cost for communicating the data packets that are associated with the second service.

Systems, methods and media for enhanced circuit-switched fallback interworking function signaling procedures for roaming user equipment

Abstract: Systems, methods and media for enhanced voice call procedures are provided. A method for enhanced voice call procedure includes receiving at a CSFB-IWF a request to provide routing information for a UE for which an incoming voice call is received. The request is received from an HLR and includes a UE identifier. The UE is operating in an LTE network. The method also includes sending a page along with a TMSI for the UE to an MME in the LTE network that can locate the UE along with the TMSI. The page signal causes the UE to switch to a legacy (3G) network. The method further includes detecting an MSC hosting the UE that is located in the legacy network. The method also includes receiving an MSRN for the UE from the hosting MSC and sending to the HLR a message including the MSRN in response to the request.

Fundamentals of Digital Switching

Abstract: 1. Networks of Switching Systems.- 2. Random Nature of Service Demands.- 3. Switching System Controls.- 4. Switching System Software.- 5. Time Division Circuit Switching.- 6. Packet Switching.- 7. The Analog Termination.- 8. Digital Terminations and Digital Signal Processing.- 9. Digital Switching System Architectures.- 10. Digital Networks.- 11. Communication Switching Architectures for Business, Industry, and Government.- 12. Integrated Service Digital Network.

Mobile station with multi-sim and tune away methods

Abstract: Apparatus and methods are disclosed to provide for a multi-SIM wireless user equipment configured for autonomous tune-away operations enabling simultaneous communication on multiple subscriptions using a shared RF chain while maintaining a voice call A multi-SIM user equipment may be capable of communicating with a first subscription and a second subscription via a transceiver The user equipment may be engaged in circuit switched communication utilizing a first channel corresponding to the first subscription associated with a first USIM; and the transceiver may be autonomously tuned away from the first channel and tuned to a second channel corresponding to the second subscription associated with a second USIM, while the circuit switched communication is ongoing, and autonomously tuned back to the first channel Other aspects, embodiments, and features are also claimed and described

A method, apparatus and system for a source-synchronous circuit-switched network on a chip (noc)

Abstract: In an embodiment, a router includes multiple input ports and output ports, where the router is of a source-synchronous hybrid network on chip (NoC) to enable communication between routers of the NoC based on transitions in control flow signals communicated between the routers. Other embodiments are described and claimed.

Handling handover requests in a communications system

Abstract: A scenario may arise in which a circuit switched (CS) bearer reservation is successful but a voice media switching from packet switched (PS) to CS performed by a mobile switching center (MSC) server fails. Certain embodiments provides systems, apparatuses, and methods for recovery from such a scenario. A method, for example, can include determining whether session transfer of a user equipment is possible in response to a request from a network element to initiate session transfer of the user equipment and reporting to the requesting network element either a generic or specific indication that the transfer is not possible, when it is determined that the session transfer is not possible.

Circuit switch pre-reservation in an on-chip network

Abstract: Techniques described herein generally include methods and systems related to circuit switching in a network-on-chip. According to embodiments of the disclosure, a network-on-chip may include routers configured to pre-reserve circuit-switched connections between a source node and a destination node before requested data are available for transmission from the source node to the destination node. Because the circuit-switched connection is already established between the source node and the destination node when the requested data are available for transmission from the source node, the data can be transmitted without the delay or with reduced delay caused by setup overhead of the circuit- switched connection. A connection setup message may be transmitted together with a memory request from the destination node to facilitate pre-reservation of the circuit-switched connection.

Hybrid optical switching for energy-efficiency and QoS differentiation in core networks

Abstract: In the future, the Internet may ultimately be constrained by energy consumption and the capability to provide quality of service (QoS). As regards the Internet core, hybrid optical switching (HOS) is promising to provide service differentiation and reduced energy consumption in respect to current electronic switching solutions. In this paper we present a novel hybrid HOS network architecture that efficiently integrates the optical packet, burst, and circuit switching on the same network. The proposed HOS network envisages the use of two parallel switches, a slow optical switch for the transmission of circuits and long bursts, and a fast switch for the transmission of packets and short bursts. The most appropriate switching method is selected for the traffic generated by different applications and the less power consuming elements are utilized for transmission, ensuring flexibility, QoS differentiation, and low energy consumption. The HOS network is organized in an overlay model with the HOS control layer performing routing, signaling, and link management, and with the HOS forwarding layer managing the reservation of resources and data scheduling. Performance and energy efficiencyof the analyzed network are assessedby means of a combined analytical and simulation approach.

A scheme of retaining LTE connection during circuit switch fall back

Abstract: The present solution enables a packet switched connection to be temporarily released at the wireless terminal for supporting voice calls over a Circuit-Switched (CS) Fallback. The packet switched connection of the LTE core network retained for a pre-defined period of time during the CSFB session allowing the user to quickly switch back to the packet switched connection when the CSFB session is shorter than the predefined period or when the voice call CSFB attempt fails. This is accomplished by the introduction of a timed buffer to control the length of time the LTE core network connection and wireless context information will be retained.

Electronic and photonic integrated circuits for fast data center optical circuit switches

Abstract: This article surveys recent work in optical switching technologies and presents a fast optical circuit switch that intimately integrates the control electrics at the chip level using a novel wafer-scale heterogeneous integration technique.

Method and apparatus for interworking SIP communication waiting with circuit switching and packet switching nodes

Abstract: A method and apparatus for interworking a session by a Mobile Switching Center (MSC) server enhanced for IP Multimedia Subsystem (IMS) Centralized Services (ICS), the method comprising receiving at the MSC an invite message and the MSC sending a setup message comprising an information element indicating a call waiting tone on when the invite message comprises a call waiting indication.

Systems and/or methods for improving packet-switched services during circuit switched fallback (csfb)

Abstract: Systems and/or methods for providing packet-switched (PS) services during a circuit- switched callback (CSFB) may be disclosed. For example, PS traffic may be offloaded over WiFi (e.g. from LTE) for CSFB during a CS call such that a PS session may be at least simultaneously maintained on WiFi during the CS voice call. The offloading may be stopped after an expiration of a timer.

Method for controlling service in radio communication system

Abstract: In a user equipment of a wireless communication system, a method for signal transmission and reception may include: sending a request for a Circuit Switched voice network (CS) service to a Gateway Mobile Switching Center (GMSC) to send and receive data to and from a second user equipment; and receiving a call reject response corresponding to the service request from the GMSC, wherein the call reject response is sent by an entity in a core network of the second user equipment. According to an embodiment, it is possible to provide a suitable service to a sender terminal making a CS service request to a receiver terminal having subscribed only to a PS service without increasing network load.

Analysis and Evaluation of Circuit Switched NoC and Packet Switched NoC

Abstract: Circuit switched NoC has, compared to packet switching, a longer setup time, guaranteed throughput and latency, higher clock frequency, lower HW complexity, and higher energy efficiency. Depending on packet size and throughput requirements they exhibit better or worse performance. In this paper we designed a circuit switched NoC and compared that with packet switched NoC. By speculation and analysis, we propose that, as packet size increases, performance decreases for packet switched NoC, while it increases for circuit switched NoC. By close examination on the router architecture, we suggest that circuit switched NoC can operate at a higher clock frequency than packet switched NoC, and thus at zero load above a certain packet size circuit switched NoC could be better than packet switched NoC in packet delay. Experiment results support our intuitions and analysis. We find the cross-over point, above which circuit switching has lower latency, is around 30 flits/packet under low load and 60-70 flits/packet under high network load.

Channel reservation protocol for over-subscribed channels and destinations

Abstract: Channels in system-wide networks tend to be over-subscribed due to the cost of bandwidth and increasing traffic demands. To make matters worse, workloads can overstress specific destinations, creating hotspots. Lossless networks offer attractive advantages compared to lossy networks but suffer from tree saturation. This led to the development of explicit congestion notification (ECN). However, ECN is very sensitive to its configuration parameters and acts only after congestion forms. We propose channel reservation protocol (CRP) to enable sources to reserve bandwidth in multiple resources in advance of packet transmission and with a single request, but without idling resources like circuit switching. CRP prevents congestion from ever occurring and thus reacts instantly to traffic changes, whereas ECN requires 300,000 cycles to stabilize in our experiments. Furthermore, ECN may not prevent congestion formed by short-lived flows generated by a large combination of source--destination pairs.