Showing papers on "Media access control published in 2012"

Analytical Study of the IEEE 802.11p MAC Sublayer in Vehicular Networks

Abstract: This paper proposes an analytical model for the throughput of the enhanced distributed channel access (EDCA) mechanism in the IEEE 802.11p medium-access control (MAC) sublayer. Features in EDCA such as different contention windows (CW) and arbitration interframe space (AIFS) for each access category (AC) and internal collisions are taken into account. The analytical model is suitable for both basic access and the request-to-send/clear-to-send (RTS/CTS) access mode. Different from most of existing 3-D or 4-D Markov-chain-based analytical models for IEEE 802.11e EDCA, without computation complexity, the proposed analytical model is explicitly solvable and applies to four access categories of traffic in the IEEE 802.11p. The proposed model can be used for large-scale network analysis and validation of network simulators under saturated traffic conditions. Simulation results are given to demonstrate the accuracy of the analytical model. In addition, we investigate service differentiation capabilities of the IEEE 802.11p MAC sublayer.

Method and apparatus for integrating different radio access technologies using carrier aggregation

Abstract: A method and apparatus are described for integrating third generation partnership project (3GPP) radio access network and an Institute of Electrical and Electronics Engineers (IEEE) 802.11 radio access technologies (RATs). This may be done at a medium access control (MAC) layer or below the MAC layer. For example, a wireless transmit/receive unit (WTRU) for multiple radio access technology (RAT) integration includes a 3GPP RAT including a radio resource control (RRC) entity, an IEEE 802.11 RAT including a medium access control (MAC) management entity, and a session management entity (SME) for mapping between the RRC entity and the MAC management entity. Combined, hybrid and split versions of logical channel prioritization (LCP) are described. The features of an LTE access stratum-service management entity (AS-SME) are also described.

IEEE 802.11ah: Advantages in standards and further challenges for sub 1 GHz Wi-Fi

Abstract: The rapid developments in Internet-of-Things (IoT) and Machine-to-Machine (M2M) communication make it necessary to design communication systems operating in different wireless spectrum as an alternative to highly congested wireless access systems. In addition, the deployment of wireless smart meter devices is ramping up and it is expected that such devices will flood the market in the near future competing for the same wireless spectrum. The IEEE 802.11ah standardization task group is developing a global Wireless LAN (WLAN) standard that will allow wireless access using carrier frequencies below 1 GHz in the ISM (Industrial, Scientific, and Medical) band and will help Wi-Fi-enabled devices to get guaranteed access for short-burst data transmissions, such as meter data. In addition to exploiting the underutilized sub 1 GHz spectrum the improved coverage range allows new applications to emerge such as wide area based sensor networks, sensor backhaul systems and potential Wi-Fi off-loading functions. This paper summarizes the IEEE 802.11ah standardization activities in progress and discusses advantages and challenges in the design of physical layer (PHY) and media access control (MAC) schemes in the sub 1 GHz band.

Long range wlan data unit format

Abstract: In a method for transmitting a data unit in a wireless communication network, a physical layer (PHY) preamble and a media access control layer (MAC) header are generated. In generating the MAC header, a first address field to include a first address and a second address field to include a second address are generated. The first, not globally unique, address indicates a communication device for which the data unit is intended or a communication device that is transmitting the data unit. The second address field indicates the other one of a communication device for which the data unit is intended or a communication device that is transmitting the data unit. The first address field and the second address field are included in the MAC header. The MAC header omits a globally unique address corresponding to the first address of the first address field.

TDMA cluster-based MAC for VANETs (TC-MAC)

Abstract: One of the challenges for Vehicular Ad-hoc Networks (VANETs) is the design of the Medium Access Control (MAC) protocol. When exchanging messages between vehicles, there are network issues that must be addressed, including the hidden terminal problem, high density, high node mobility, and data rate limitations. A cluster-based MAC scheme is needed in VANETs to overcome the lack of specialized hardware for infrastructure and the mobility to support network stability and channel utilization. This paper presents a MAC algorithm for vehicular ad-hoc networks using a new method for TDMA slot reservation based on clustering of vehicles. Our algorithm aims to decrease collisions and packet drops in the channel, as well as provide fairness in sharing the wireless medium and minimizing the effect of hidden terminals.

Aggregate Interference Modeling in Cognitive Radio Networks with Power and Contention Control

Abstract: In this paper, we present interference models for cognitive radio (CR) networks employing various interference management mechanisms including power control, contention control or hybrid power/contention control schemes. For the first case, a power control scheme is proposed to govern the transmission power of a CR node. For the second one, a contention control scheme at the media access control (MAC) layer, based on carrier sense multiple access with collision avoidance (CSMA/CA), is proposed to coordinate the operation of CR nodes with transmission requests. The probability density functions (PDFs) of the interference received at a primary receiver from a CR network are first derived numerically for these two cases. For the hybrid case, where power and contention controls are jointly adopted by a CR node to govern its transmission, the interference is analyzed and compared with that of the first two schemes by simulations. Then, the interference PDFs under the first two control schemes are fitted by log-normal PDFs to reduce computation complexity. Moreover, the effect of a hidden primary receiver on the interference experienced at the receiver is investigated. It is demonstrated that both power and contention controls are effective approaches to alleviate the interference caused by CR networks. Some in-depth analysis of the impact of key parameters on the interference of CR networks is given as well.

A 2-Gb/s Throughput CMOS Transceiver Chipset With In-Package Antenna for 60-GHz Short-Range Wireless Communication

Abstract: This paper presents a fully integrated CMOS 60-GHz transceiver chipset for short-range and high-speed wireless communication. The target application of the short-range communication is less than 5-cm communication distance and more than 2-Gb/s throughput for file transfer. In order to achieve file transfer, physical (PHY) layers with error packet correction and media access control (MAC) layer with frame-exchanging function are implemented. The MAC is designed to have a high-efficiency feature due to short interval DATA/Acknowledgement (ACK) frame exchange. It is realized by fast transmitter (TX)/receiver (RX) switching. A bonding wire-based in-package antenna is adopted using a standard BGA package without any off-chip 60-GHz components. The proposed chipset is composed of two chips, an RF chip with in-package antenna, and a baseband chip including PHY and MAC layer. The fabricated chipset achieves 2.62-Gb/s PHY data rate, 2.07-Gb/s MAC throughput, and energy consumption of 651 pJ/bit in 3-cm distance.

Content and RAN aware network selection in multiple wireless access and small-cell overlay wireless access networks

Abstract: Methods for steering the access technology selection by a mobile device in an overlay Small-Cell and Macro Network, such as UMTS, LTE, CDMA, or WIFI are disclosed. This selection determination is based on the observed, real-time correlated and estimated network congestion, content-awareness, application/service expectations, and other criteria. Methods and procedures to influence network selection or control currently selected networks by propagating real-time correlated and consolidated information on a plurality of Radio Access Technologies to Access Points, or modifying the list of alternative Radio Access Technologies available at a location using standards defined mechanisms and parameters are identified. Additionally, steering content access and delivery through alternative access technologies, based on anticipated network usage by user's service activation, and the knowledge of the type, state and resource usage of a plurality of access networks when a mobile device connects to multiple access technologies through in-band or out-of-band mechanisms is identified.

Vehicular Ad-hoc Networks

Abstract: Modern day's vehicles require advanced communication system on board to enable passengers benefit the most from available services. IEEE 802.11p is the new extension of IEEE 802.11 standards; especially proposed for the high vehicular environment. The WAVE documentation represents enhancements to the Media Access Control (MAC) and Physical (PHY) layer of IEEE 802.11 standards to work efficiently in high vehicular environment. In this research work, the main emphasis is on the new IEEE 802.11p enhancement of MAC and PHY layers. More specifically, the target of this research is to setup a simulation environment which will allow us to investigate the use of real time voice application, using IEEE 802.11p (WAVE) enhance setting, in a single hop and multi-hop environment where nodes are not directly connected. Also, the evaluation of transmission between moving nodes are tested by simply sending and receiving FTP file between them with varying speed of the moving nodes.

System and method for VXLAN inter-domain communications

Abstract: VXLAN inter-domain communications and packet forwarding are supported between a virtual machine (VM) in a Virtual eXtensible Local Area Network (VXLAN) domain and an external client or another domain via a Layer Two (L2)/Layer Three (L3) switch, router, or network. A VXLAN Tunnel End Point (VTEP) coupled to the VM at a server and to the L2/L3 switch, router, or network and associated with the VXLAN domain is configured to implement a method for enabling the VXLAN inter-domain communications. The method includes receiving a packet at the (VTEP), replacing a source or destination Media Access Control (MAC) address in the packet if the packet is part of communications between a VXLAN domain for the VMs and an external component without encapsulating or decapsulating the packet, and forwarding the packet. Alternatively, the VTEP encapsulates or decapsulates an incoming packet if the packet is part of a VXLAN internal domain communications.

Methods and apparatus for a common control protocol for wired and wireless nodes

Abstract: In some embodiments, an apparatus comprises of a control module implemented in at least one of a memory or a processing device that is configured to receive, via a network and from a wireless access point or an access network node, a control packet defined based on a control protocol. The control packet is associated with at least one control function of the wireless access point or access network node. The control module is configured to determine a status of an access network node based on the control packet from the access network node. The control module is configured to send via the network, a response to the access network node based on the status of the access network node.

System and method for optimizing within subnet communication in a network environment

Abstract: A method for optimizing within subnet communication in a network environment is provided and includes receiving, at a Top-Of-Rack (ToR) switch, an advertisement from an attached host belonging to a subnet of a network environment, seeking a Media Access Control (MAC) address of a remote host in the subnet, looking up a host information database in a control plane of the ToR switch, and responding to the advertisement with the MAC address of the remote host. If the MAC address is not found, the ToR switch may not respond to the advertisement. The method can further include receiving, at the ToR switch from a remote ToR switch in the subnet, a host information of the remote host in the subnet, including an IP address and the MAC address of the remote host, the Layer 2 broadcast domain it belongs to, and storing the host information in the host information database.

Scalable media access control protocol synchronization techniques for fabric extender based emulated switch deployments

Abstract: Techniques are provided to prevent switches in a data center fabric path environment with fabric path extension devices from media access control (MAC) address flooding and MAC address table overflow. In such an environment, endpoints associated with virtual port channels are connected to multiple switches which normally would perform MAC address flooding across all switch forwarding engines. The switches in the fabric path exchange MAC synchronization messages based on source/destination specific connectivity such that MAC broadcast messages that advertise source/destination MAC addresses for endpoints do not have to be repeatedly sent and their corresponding MAC lookup tables do not have to be updated or include unnecessary MAC table entries.

Apparatus and methods for media access control header compression

Abstract: Systems, methods, and devices for communicating packets having a plurality of types are described herein. In some aspects, the packets include a compressed MAC header. In some aspects the packets include an acknowledgment (ACK) frame. The fields included in a particular packet type may be based on the type of information to be communicated to the receiving device.

Throughput, energy consumption, and energy efficiency of IEEE 802.15.6 body area network (BAN) MAC protocol

Abstract: Low-powered and light-weight sensor nodes will be deployed for e-health services in wireless body area networks (WBANs). Recently, the Institute of Electrical and Electronic Engineering (IEEE) introduced a new standard, IEEE 802.15.6 for wireless body area communications. The goal of this standard is to specify several physical layers (PHY) and medium access control (MAC) layer protocols for variety of applications with various QoS requirements. In this paper, we evaluate the performance of the IEEE 802.15.6 WBAN MAC protocol in terms of throughput, power consumption, and energy efficiency under unsaturated conditions. We develop a discrete-time Markov chain based analytical model to evaluate the performance of CSMA/CA based WBAN MAC protocol during contention access phases. To verify the numerical results obtained from analytical model, we performed simulations and compared the results.

A power efficient MAC protocol for wireless body area networks

Abstract: Applications of wearable and implanted wireless sensor devices are hot research area. A specialized field called the body area networks (BAN) has emerged to support this area. Managing and controlling such a network is a challenging task. An efficient media access control (MAC) protocol to handle proper management of media access can considerably improve the performance of such a network. Power consumption and delay are major concerns for MAC protocols in a BAN. Low cost wakeup radio module attached with sensor devices can help reduce power consumption and prolong the network lifetime by reducing idle state power consumption and increasing sleep time of a BAN node. In this article, we propose a new MAC protocol for BAN using out of band (on-demand) wakeup radio through a centralized and coordinated external wakeup mechanism. We have compared our method against some existing MAC protocols. Our method is found to be efficient in terms of power consumption and delay.

Provisioning QoS controlled media access in vehicular to infrastructure communications

Abstract: The emerging IEEE 802.11p standard adopts the enhanced distributed channel access (EDCA) mechanism as its Media Access Control (MAC) scheme to support quality-of-service (QoS) in the rapidly changing vehicular environment. While the IEEE 802.11 protocol family represents the dominant solutions for wireless local area networks, its QoS performance in terms of throughput and delay, in the highly mobile vehicular networks, is still unclear. To explore an in-depth understanding on this issue, in this paper, we develop a comprehensive analytical model that takes into account both the QoS features of EDCA and the vehicle mobility (velocity and moving directions). Based on the model, we analyze the throughput performance and mean transmission delay of differentiated service traffic, and seek solutions to optimally adjust the parameters of EDCA towards the controllable QoS provision to vehicles. Analytical and simulation results are given to demonstrate the accuracy of the proposed model for varying EDCA parameters and vehicle velocity and density.

Systems and method for booting devices in a multiple-card computing system

Abstract: A method for booting devices in a multi-card computing system comprising a plurality of cards connected to a shared backplane may include: dynamically generating a Media Access Control (MAC) addresses for at least some of the devices in the computing system, the dynamically generated MAC address for each device including information regarding the location of that device within the multi-card computing system; a boot management system receiving a boot-related information request from a particular device in the multi-card system, the boot-related information request comprising a request for particular boot-related information for facilitating a boot process for the requesting device, and including the MAC address of the requesting device; and the boot management system determining whether to send a response to the requesting device with the requested boot-related information based at least on the information in the MAC address regarding the location of the requesting device within the multi-card computing system.

Achievable transmission capacity of cognitive mesh networks with different media access control

Abstract: Spectrum sharing is an emerging mechanism to resolve the conflict between the spectrum scarcity and the growing demands for the wireless broadband access. In this paper we investigate the achievable transmission capacity of a wireless backhaul mesh network that shares the spectrums of the underutilized cellular uplink over the underlay spectrum sharing model with several commonly adopted medium access control protocols: slotted-ALOHA, CSMA/CA, and TDMA. By employing stochastic geometry, we derive the probabilities for a packet to be successfully transmitted in the primary cellular uplink and the secondary mesh networks. The achievable transmission capacity of the secondary network with outage probability constraints from both the primary and the secondary systems is obtained according to Shannon's Theory. The capacity region and the achievable capacity when the outage probabilities equal their corresponding threshold values are analyzed numerically and the results illustrate the effect of adjusting the mesh network parameters on the achievable transmission capacity under different MAC protocols.

Avoiding collisions between IEEE 802.11 and IEEE 802.15.4 through coexistence aware clear channel assessment

Abstract: More and more devices are becoming wirelessly connected. Many of these devices are operating in crowded unlicensed bands, where different wireless technologies compete for the same spectrum. A typical example is the unlicensed ISM band at 2.4 GHz, which is used by IEEE 802.11bgn, IEEE 802.15.4, and IEEE 802.15.1, among others. Each of these technologies implements appropriate Media Access Control (MAC) mechanisms to avoid packet collisions and optimize Quality of Service. Although different technologies use similar MAC mechanisms, they are not always compatible. For example, all CSMA/CA-based technologies use Clear Channel Assessment (CCA) to detect when the channel is free; however, in each case it is specifically designed to improve detection reliability of the specific technology. Unfortunately, this approach decreases the detection probability of other technologies, increasing the amount of cross-technology collisions. In this article, we introduce the concept of coexistence aware CCA (CACCA), which enables a node operating in one technology to backoff for other coexisting technologies as well. As a proof of concept, we analyze the Packet Error Rate(PER) incurred by an IEEE 802.15.4 network in the presence of IEEE 802.11bg interference, and assess the PER reduction that is achieved by using CACCA.

Wireless fidelity (WIFI) based layered positioning system and implementing method

Abstract: The invention discloses a wireless fidelity (WIFI) based layered positioning system and an implementing method. The system comprises a receiving interface, a judging module, a positioning module and a display module. The implementing method of the system includes firstly, acquiring wireless signal intensities and a media access control (MAC) address of an access point (AP); secondly, judging a storey where a mobile terminal user is located; thirdly, positioning the mobile terminal user; and fourthly, displaying a specific position of the mobile terminal user on the storey. According to the WIFI based layered positioning system and the implementing method, indoor layered mobile terminal users can be timely and accurately positioned, reference points are expanded by means of participation of the users, costs are saved, and simultaneously, accuracy of positioning can be guaranteed.

Generating Route-Specific Origin-Destination Tables Using Bluetooth Technology

Abstract: Bluetooth media access control (MAC) data collection technology has emerged as a forerunner in the suite of passive data collection techniques used in travel time and origin-destination (O-D) data collection efforts because of its low cost, ease of implementation, and richness of the resultant data set. With a few notable exceptions, the majority of published research and practical applications of Bluetooth MAC data to date have focused on travel speed analysis. This paper aims to add to the existing literature on Bluetooth O-D data research by describing an analytic approach used to develop route-specific O-D tables for a 15-mi corridor in Jacksonville, Florida. The data from this project were successfully used as an after-model validation tool for base and future year toll revenue forecasts. Bluetooth MAC data were shown to provide a robust and rich data set capable of providing insight into the travel patterns of users in a corridor that would not be easily or efficiently achieved with other data colle...

Smart meter media access control (MAC) for single user, multiple user, multiple access, and/or MIMO wireless communications

Abstract: Smart meter media access control (MAC) for single user, multiple user, multiple access, and/or MIMO wireless communications. Different types of wireless communication devices may be implemented within various wireless communication systems. Some of these devices may be implemented to communicate sensing and/or measurement to one or more other devices. For example, certain devices may be implemented to perform monitoring associated with any of a number of services provided by service providers (e.g., electricity, natural gas, water, Internet access, telephone service, and/or any other service). In accordance with such sensing and/or measurement related applications, a given device need not necessarily be awake or at a fully operative state at all times. Appropriate coordination, scheduling, communication medium access, etc. among potentially many implemented devices ensures effective communication and gathering of such sensing and/or measurement related data (e.g., using one or more service period (SP) announcements, various communication medium access options, etc.).

Load balancing overlay network traffic using a teamed set of network interface cards

Abstract: A system includes a server including: logic adapted for receiving traffic from a virtual machine (VM), the traffic including at least one packet, logic adapted for hashing at least a portion of the at least one packet according to a hashing algorithm to obtain a hash value, and logic adapted for selecting an uplink based on the hash value; at least one accelerated network interface card (NIC), each accelerated NIC including: network ports including multiple Peripheral Component Interconnect express (PCIe) ports adapted for communicating with the server and a network, each network port including an uplink, logic adapted for encapsulating the at least one packet into an overlay-encapsulated packet, logic adapted for storing a media access control (MAC) address corresponding to the selected uplink as a source MAC (SMAC) address in an outer header of the overlay-encapsulated packet, and logic adapted for sending the overlay-encapsulated packet via the selected uplink.

MAC protocol identification approach for implement smart cognitive radio

Abstract: Cognitive radio (CR) is regarded as a solution to address the spectrum scarcity issue in wireless communications. In CR, an unlicensed network user is enabled to dynamically/adaptively access the frequency channels according to the current state of the radio environment and, therefore, CR refers to a smart radio as defined in an “observe-learn-decision” cognitive cycle. In this paper, we consider the medium access control (MAC) protocols as radio parameters in the cognitive cycle, and propose a new approach called MAC protocol identification to implement smart cognitive MAC. The MAC protocol identification approach enables CR users to sense and identify the network MAC protocol types. The identification results will be used by CR users to adaptively change their transmission parameters in order to improve the spectrum hole utilization efficiency, save energy, minimize the interference to the primary users, as well as facilitate communications among heterogeneous CR networks. To verify that the MAC protocol identification is feasible, we propose a MAC identification process based on machine learning techniques in this paper, and some experimental results are presented.

Mobile terminal and method for realizing Bluetooth communication between mobile terminals

Abstract: The invention discloses a mobile terminal, which comprises a base band, an NFC (near field communication) module and a Bluetooth module, wherein the NFC module and the Bluetooth module are respectively connected with the base band; the NFC module is used for carrying out NFC with other mobile terminals, obtaining a Bluetooth MAC (media access control) address of the mobile terminal from the base band, receiving Bluetooth MAC addresses of other mobile terminals and sending the Bluetooth MAC addresses of other mobile terminals into the base band; the Bluetooth module is used for carrying out Bluetooth communication with other mobile terminals; the base band obtains the Bluetooth MAC address of the mobile terminal, and receives the Bluetooth MAC addresses of other mobile terminals, which are from the NFC module; according to the Bluetooth MAC address of the mobile terminal and the Bluetooth MAC addresses of other mobile terminals, UUID (universally unique identifier) is generated; and according to the UUID, the Bluetooth communication between the mobile terminal and other mobile terminals is established. The invention also discloses a method for realizing Bluetooth communication between mobile terminals. According to the mobile terminal disclosed by the invention, the opposite-side Bluetooth MAC address is obtained by the NFC to realize the direct pairing of the Bluetooth.

System and method for traffic signaling and control in a wireless network

Abstract: A system and method are provided for traffic signaling in wireless or sensor networks. The system and method use information or bits in a Signal Field (SIG) of Physical Layer (PHY) preamble in a packet to provide traffic control information. An embodiment method implemented by a network component comprises indicating a traffic direction and a traffic type for traffic control in a SIG in a frame and transmitting the frame including the SIG. Another method comprises receiving in a frame a SIG for traffic control that indicates a transmission type and decoding the SIG field to determine whether to process remaining information in the frame if the frame comprises data payload or a Media Access Control (MAC) header.

Wavelength management in time and wavelength division multiplexed passive optical networks (TWDM-PONs)

Abstract: Time and wavelength division multiplexed passive optical network (TWDM-PON) is one of the most promising candidates of the next generation optical access system beyond 10Gb/s. The TWDM-PON system stacks multiple 10Gigabit PONs (XG-PONs) by employing tunable transmitters and tunable receivers at ONUs. In the TWDM-PON media access control (MAC) layer, wavelength management becomes a critical issue of resource sharing and assignment. In this paper, we propose a mechanism to manage multiple wavelengths in the TWDM-PON system. We also model this problem by using multiprocessor scheduling analysis. Two types of heuristic algorithms have been proposed to relax the NP-hard complexity problem and promote online implementation. A TWDM-PON prototype system has been built to evaluate its performance. The proposed two algorithms have been implemented in the prototype system to test their wavelength tuning cost and load balancing capability. Analysis and test demonstrate salient results. To the authors' best knowledge, this is the first work of implementing the multiple wavelength management mechanism in an actual TWDM-PON prototype system, and the reported results in this paper benefit the ongoing next generation passive optical network stage 2 (NG-PON2) research and standards efforts.