Analysis of Path Selection Algorithms for Heterogeneous Networks
Kurzbeschreibung
The meshed topology of a home network allows choosing alternative paths for a quality of service flow. The
establishment and release of Gigabit flows creates a dynamic environment in which the optimal flow/path combination
might require re-selection of paths. The FP7 European Project OMEGA investigates the performance of such Gigabit
home networks. Todays homes are equipped with a multitude of devices using several wired or wireless communication
technologies forming a heterogeneous, meshed home network. A common set of layer 2 (L2) technologies found in homes
contains Wireless Local Area Networks, Ethernet cables, and Powerline adapters whereas Plastic Optical Fiber (POF), and
60GHz technologies are emerging as well. Furthermore future HNs are hybrid mesh networks [2] which combine
infrastructure and client meshing and have at least a single point of connection to the Internet, called the home gateway
(HG). Communication from and to the Internet goes through this HG. In case that data is exchanged between two clients of
the bridged L2 HN the communication is peer to peer (P2P) and data packets usually must not be routed via
the HG. One task is to develop appropriate communication protocols and common control
functions for elements in such networks. One of todays challenges is to provide service continuity in those highly
heterogeneous networks. The selection of appropriate paths has to take the demands of the application into account.
In this work several path selection algorithms should be investigated and compared analytically using Signal Flow Graphs and optimization theory. The path selection algorithms should support Gigabit flows with Quality of Service (QoS)
guarantees and additional constraints, e.g. exclude routes. Therefore the capabilities of the links have to be considered and
appropriate paths have to be chosen so that the required QoS can be satisfied with a given probability. The signaling
overhead should be investigated in terms of required amount of signaling messages, the time for path establishment, and
update. Path selection can be performed either on demand or proactively. The decision making could be done in a
distributed or centralized manner. The Path selection should maximize the number of supported Gigabit flows within the
home network for a broad range of typical home networking scenarios as well as usage scenarios. Therefore existing path
selection algorithms with QoS support should be reviewed and a concept should be proposed that scales for home
networks. The concept should consider existing protocols like IEEE 802.11s HWMP and AODVQOS. The monitoring of
existing links should be done with the help of link triggers as defined by IEEE 802.21. During the evaluation the proposed
concept should be investigated using different link metrics and the network utilization should be compared with a home
network without path selection.
The following work items shall be handled:
- Describe the state of the art of path selection protocols, e.g. IEEE 802.11s HWMP, AODVQOS
- Describe typical home networking and usage scenarios
- Create a concept that allows having flows with QoS guarantees within heterogeneous home networks.
- Provide a concept that allows to monitor existing links
- Evaluation of the algorithms using different link metrics and multimedia streams
- Evaluation of the signaling overhead and the required time for path re-selection
- Description of the obtained results
- Final presentation (two intermediate presentations)
Letzte Änderung: 23-10-09
