Search results for "Multicast"
showing 10 items of 32 documents
The Random Neural Network Model for the On-line Multicast Problem
2005
In this paper we propose the adoption of the Random Neural Network Model for the solution of the dynamic version of the Steiner Tree Problem in Networks (SPN). The Random Neural Network (RNN) is adopted as a heuristic capable of improving solutions achieved by previously proposed dynamic algorithms. We adapt the RNN model in order to map the network characteristics during a multicast transmission. The proposed methodology is validated by means of extensive experiments.
An Efficient Distributed Algorithm for Generating Multicast Distribution Trees
2005
Multicast transmission may use network resources more efficiently than multiple point-to-point messages; however, creating optimal multicast trees (Steiner Tree Problem in Networks) is prohibitively expensive. For this reason, heuristic methods are generally employed. Conventional centralized Steiner heuristics provide effective solutions, but they are unpractical for large networks, since they require complete knowledge of the network topology. This paper proposes a distributed algorithm for the heuristic solution of the Steiner Tree Problem. The algorithm allows the construction of effective distribution trees using a coordination protocol among the network nodes. The algorithm has been i…
Enabling Retransmissions for Achieving Reliable Multicast Communications in WSNs
2016
To ensure end-to-end reliable multicast or broadcast transmissions in IEEE 802.15.4 based wireless sensor networks WSNs) is a challenging task since no retransmission and acknowledgment mechanisms are defined in such WSNs. In this paper, we propose three retransmission enabled multicast transmission schemes in order to achieve reliable packet transmissions in such networks. Different from the legacy CSMA/CA principle, these schemes allow a sending or forwarding node to retransmit a packet if necessary and enable implicit or/and explicit acknowledgment for multicast services. Simulations are performed in order to assess the performance of these schemes in terms of number of retransmissions, …
Priority-oriented multicast transmission schemes for heterogeneous traffic in WSNs
2016
To ensure quality of service (QoS) for heterogeneous traffic in IEEE 802.15.4 based wireless sensor networks (WSNs) is a challenging task since no traffic prioritization mechanism is defined in such WSNs. In this paper, we propose two priority-oriented multicast transmission schemes to provide QoS for heterogeneous traffic in WSNs. Contrary to the legacy CSMA/CA and FIFO principles, these schemes differentiate self-generated or received traffic and give priority to delay-sensitive traffic with respect to channel access and packet scheduling. Simulations are performed in order to assess the performance of these schemes in terms of end-to-end delay, energy consumption, packet delivery ratio, …
What's New for QoS in IEEE 802.11?
2013
Two amendments to IEEE 802.11 have recently been published: 802.11aa and 802.11ae. Both enhance Quality of Service (QoS) provisioning in Wi-Fi networks by providing support for multicast transmission, enhanced audio video streaming, coping with inter-network interference, and improved prioritization of management frames. The proposed solutions either extend mechanisms already existing in the standard or introduce new ones. Therefore, it is important for researchers to understand the new functionalities. To this end we provide the first description of these latest mechanisms: we present the motivation behind them, explain their design principles, provide examples of usage, and comment on com…
Evaluation and improvement of collective flooding in WSNs with various link correlations
2015
One of the main challenges confronted by wireless sensor networks (WSNs) is to reduce energy consumption of nodes for the purpose of network lifetime extension. In the literature, many backbone based protocols such as connected dominating set (CDS) and broadcast or multicast based protocols are employed in order to improve network performance in terms of metrics like energy consumption, number of transmissions and dissemination delay. In this paper, we evaluate the performance of a recently proposed transmission protocol known as collective flooding (CF), which is based on link correlation, under various link correlation conditions. Through simulations and analyses we demonstrate that altho…
Multicast TV over WLAN in a University Campus Network
2009
One of the multimedia services offered by the campus network of the Polytechnic University of Valencia is TV over IP. This service works well in the devices connected directly to the wired network but we have detected some problems when the receivers access to the campus network through wireless IEEE 802.11, especially when devices roam across the Campus. In this paper we propose and evaluate a server-based solution to minimize the packet loss and reduce the lack of service when the mobile devices roam from an Access Point to another Access Point in the wireless network. This solution uses a location system to modify the behaviour of standard multicasting protocols in order to get a near-se…
Multicast access control concept for xDSL-customers
2006
Multicast is a tempting possibility for many broad- band services. It makes possible to deliver one data-stream to several receivers simultaneously. IP-Multicast is based on an open group concept. This means that it is possible for all the users to join the group and thus receive the data. The open concept is also the main reason why multicast has not been taken in wider use. There is two different solution to solve this problem, group access control and multicast data encryption. Group access control mechanisms focuses on restricting the group membership at the users edge device. Traffic encryption scheme relies on end-to-end encryption, so a key management architecture is also needed. We …
Quality of Service Multicasting over Differentiated Services Networks
2003
This paper proposes a solution to support real-time multicast traffic with Quality of Service (QoS) constraints over Differentiated Services (DiffServ) IP networks. Our solution allows multicast users to dynamically join and leave the multicast tree. Moreover, it allows a multicast user which has negotiated a best-effort session to upgrade to a QoS-enabled session. Our solution is backward compatible with the Protocol Independent Multicast (PIM) scheme. It combines two ideas. First, resource availability along a new QoS path is verified via a probe-based approach. Second, QoS is maintained by marking replicated packets with a special DSCP value, before forwarding them on the QoS path.
Multicast polling and efficient voip connections in ieee 802.16 networks
2007
IEEE 802.16 standard defines the wireless broadband access network technology called WiMAX which introduces several interesting advantages including its the support for quality of service (QoS) at the MAC layer. Its several features, such as multicast polling support the base station (BS) to provide the QoS guarantees for subscriber stations (SSs). The specification, however, does not define very exactly how this optional multicast polling technique should be used. We propose a way to use this feature on the base stations and also suggest an addition to the specification, to serve several different delay requirements. To test the proposed solution and the performance of the multicast pollin…