The invention relates to interconnecting communication nodes in a mesh network.
A wireless mesh network is a communications network often made up of radio nodes organized in a mesh topology. The coverage area of the radio nodes working as a single network is sometimes called a mesh cloud. Access to this mesh cloud is dependent on the radio nodes working in harmony with each other to create a radio network. A mesh network should be reliable by offering redundancy. When one node can no longer operate, the rest of the nodes can still communicate with each other, directly or through one or more intermediate nodes. A wireless mesh network may be seen as a type of wireless ad hoc network, where all radio nodes are static and doesn't experience direct mobility. Wireless mesh architecture is often a first step towards providing high-bandwidth network over a specific coverage area. Wireless mesh architecture's infrastructure is, in effect, a router network minus the cabling between nodes. A mesh network is typically built of peer radio devices that don't have to be cabled to a wired port like traditional WLAN access points (AP) do. Mesh architecture typically sustains signal strength by breaking long distances into a series of shorter hops. Intermediate nodes may not only boost the signal, but cooperatively make forwarding decisions based on their knowledge of the network, i.e., performs routing. Such an architecture may, with careful design, may provide high bandwidth, spectral efficiency, and economic advantage over the coverage area.
Consequently, there is a real need to facilitate effective operation of a mesh network in providing reliable communications for a data user.
The present invention supports a communication node having a downstream component logically connected over a downlink to provide communications for a data user.
With an aspect of the invention, the communication node has a plurality of upstream components, the plurality of upstream components including a first upstream component being logically connected to a first data destination over a first uplink. The communication node also has a controlling component that selects the first upstream component based on a first comparative link quality of the first uplink, where the first downstream component is electrically coupled to the first upstream component.
With another aspect of the invention, the communication node of claim 1, the controlling component determines the first comparative link quality from a plurality of link quality metrics, where a corresponding weight is associated with each link quality metric.
With another aspect of the invention, an upstream component includes an upstream radio and an upstream directional antenna.
With another aspect of the invention, a downstream component includes a downstream radio and a downstream directional antenna.
This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the clamed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.
The foregoing summary of the invention, as well as the following detailed description of preferred embodiments, is better understood when read in conjunction with the accompanying drawings, which are included by way of example, and not by way of limitation with regard to the claimed invention.
Overview
Embodiments of the invention support directional antennas providing performance improvement while offering desirable characteristics of mesh network operation. However, embodiments of the invention may have a network topology with omnidirectional coverage patterns.
Mesh Network
Immediately below this layer are several “layer 1” access points 215 and 216, each with its own connection to router 212. Each of these is equipped with its own (typically directional) antennas 217 and 218.
Mesh network 200 include intermediate nodes 220, 221, 222, and 223, each equipped with one or more upstream antennas 230-235, and one or more downstream antennas 246. Mesh network 200 provides connection flexibility. For example, communication node 220 may connect directly with access point 215 via antenna 230, and/or with access point 216 via antenna 231. Similarly, communication nodes 221 and 222 may connect with both or either access points 215 and 216. (In the following discussion, a communication node is referred as a node.)
With embodiments of the invention, node 223 does not connect to either access points 215 and 215, but rather can reach either of node 220 or node 221 through antenna 236. Node 223 can also communicate with node 222 via antenna 237. It could also be located as to reach access point 216 through either antenna. With embodiments of the invention, a layer of links may be included or skipped.
Terminal nodes 250, 251, and 252 are each equipped with one upstream antenna, corresponding to antennas 260, 261, and 262, respectively, and are connected to wired IP connections 270, 271, and 272, respectively. Terminal nodes 250, 251, and 252 may also be equipped with two or more upstream antennas. In such a case, terminal module 250 may configure a connection to node 220 through antenna 241 and to node 221 through antenna 243. Node 251 connects only to node 221, while node 252 connects only to node 223 in the exemplary configuration shown in
Operation
As illustrated in
Logic element 109 may employ one or more of several methods to differentiate among the links available as will be discussed.
Link Quality Metrics
There are several ways to choose among the links available at any one node in the mesh. These include the following:
Combinatorial Link Evaluation
where the Sx factors are the weights corresponding to the associated parameter.
With embodiments of the invention, the actual values in EQ. 1, the scaling for each parameter, and the actual parameters selected for evaluation may be different for different mesh networks. For example, if the observed packet error rate and the variation of packet arrival time are considered significant parameters for a mesh network, the corresponding factors may be added to the evaluation matrix in
Central Control
In an alternative embodiment, control of each link can be asserted from a central point, where one of two command schemes may be implemented: automatic control, or manual control. In either case, logic at the central point may keep track of one or more of the aforegoing evaluation methods, either by querying logic element 109 in each node, or by direct measurement. With the manual method, this information may be presented for the use of a human operator, most desirably in the form of a system diagram or graph with the characteristics of each link clearly displayed, for instance, by showing better links as thicker lines. The human operator would then make the appropriate decisions about routing at each of the nodes, using for example a computer mouse or keyboard to indicate the links to be used.
With the case of automatic implementation, the logic at the central control point may use the link quality information gathered as described above to choose the preferred link or links for each path, in the same manner as the automatic routing for a mapping program chooses a route for a driver to follow—by tracing a number of alternative routes, and picking the one with the best overall performance. The route so chosen may then be displayed on a computer screen, using the same sort of techniques described for presentation to a human operator.
Alternative Implementations
There of course is no reason to limit the type of system controlled by this logic to wireless system. Links may assume a wireless configuration, as shown in
As can be appreciated by one skilled in the art, a computer system with an associated computer-readable medium containing instructions for controlling the computer system can be utilized to implement the exemplary embodiments that are disclosed herein. The computer system may include at least one computer such as a microprocessor, digital signal processor, and associated peripheral electronic circuitry.
Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.
Number | Date | Country | |
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60951540 | Jul 2007 | US |