737 research outputs found

    KALOHA:  ike  i ke ALOHA

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    A new family of channel-access schemes  called KALOHA  (for ``Knowledge in ALOHA") is introduced.  KALOHA consists of modifying the pure ALOHA  protocol  by  endowing nodes with knowledge regarding the local times when packets  and acknowledgments are received,  and sharing  estimates of channel utilization at the medium access control (MAC) layer. The only physical-layer feedback needed   in KALOHA is the reception of  correct data packets and their ACKs. A  simple Markov-chain model is used  to  compare the throughput of KALOHA with ALOHA and slotted ALOHA. The analysis takes into account the amount of knowledge that nodes have and  the  effect of  acknowledgments and turnaround latencies.  The results  demonstrate the  benefits  derived from using  and sharing knowledge of channel utilization at the MAC layer.  KALOHA is more stable  than ALOHA and attains  more than double  the throughput of  ALOHA,  without the need for carrier sensing, requiring time slotting at the physical layer, or using other physical-layer mechanisms

    A fault-tolerant forwarding strategy for interest-based information centric networks

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    We show that the forwarding strategies in the named data networking (NDN) architecture and the original content centric networking (CCN) architecture cannot ensure that Interests return the requested data objects when routing-table loops exist in a stable or dynamic network. We also show that no correct Interest forwarding strategy that allows Interest aggregation can be designed solely on the basis of identifying Interests uniquely in order to detect Interest loops. We introduce SIFAH (Strategy for Interest Forwarding and Aggregation with Hop-Counts).  SIFAH prevents or detects Interest loops when Interests are aggregated or forwarded over one or multiple paths. As a result, it is far more efficient than the forwarding strategy in NDN and the original CCN proposal. SIFAH operates by having forwarding information bases (FIB) store the next hops and number of hops to named content prefixes, and by using Interests that state the names of requested content and hop counts that reflect the information in their FIBs

    A distributed cross-layer routing protocol with channel assignment in multi-channel MANET

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    An innovative cross-layer routing approach, MCORCA (Multi-Channel On-demand Routing with Coordinate Awareness), is presented that utilizes multiple channels to im- prove the performance of wireless ad-hoc networks. The proposed cross-layer scheme adapts the strategy of channel assignment and the mechanism of dealing with conflicts. Channels are divided into a control channel and data channels; the control channel is used for scheduling, and data channels are used for data transmissions. MCORCA is an extension of an on- demand routing protocol for single channel wireless networks, called ORCA (On-demand Routing with Coordinates Awareness). Simulation results indicate that MCORCA yields a significant capacity improvement as well as lower end-to-end delays by using multiple channels

    A Simple Solution to Scale-Free Internet Host Mobility

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    We introduce a simple solution for the support of host mobility in the Internet called DIME (Dynamic Internet Mobility for End-Systems). DIME is based on dynamic address translation between the transport and network layers of end hosts, combined with a new out-of-band protocol that updates host-address bindings between communicating hosts opportunistically. It does not require modifications to the end-host operating systems, end-user applications, existing communication protocols or hardware, or the domain name system and any host-identifier namespace. A number of experiments based on a Linux daemon implementation of DIME are used to show that DIME is deployable on a wide range of hardware, and that it outperforms existing mobility proposals such as MIPv6 and HIP across a wide range of performance metrics

    Proximity-driven social interactions and their impact on the throughput scaling of wireless networks

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    We present an analytical framework to investigate the interplay between a communication graph and an overlay of social  relationships.  We focus on geographical distance as the key element that interrelates the concept of routing in a communication network with the dynamics of interpersonal relations on the corresponding social graph. We identify  classes of social relationships that let the ensuing system  scale---i.e., accommodate a large number of users given only finite amount of resources. We establish that geographically concentrated communication patterns are indispensable to network scalability. We  further examine the impact of such proximity-driven interaction patterns on the throughput scaling of wireless networks, and show that, when social communications are geographically localized, the maximum per-node throughput scales approximately as 1/logn1/\log n, which is significantly better than the well-known bound of 1/nlogn1/\sqrt{n \log n} for the uniform communication model
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