Method and apparatus for assigning channels for a multi-radio wireless mesh network

A device that assigns channels to links in a wireless mesh network, the network comprising a first mesh router and a second mesh router, the first mesh router having a first radio component and the second mesh router having a second radio component, wherein the first mesh router and the second mesh router are within transmission ranges of the first radio component and the second radio component, the first radio component having a first unidirectional link and a second unidirectional link between the first mesh router and the second mesh router, directions of the first unidirectional link and the second unidirectional link are opposite to each other, the device comprising:

• a link load measuring means that measures a first average busy time of the first unidirectional link and a second average busy time of the second unidirectional link, wherein the first average busy time is a period of time in which the first unidirectional link transmits traffic over a given period and the second average busy time is a period of time in which the second unidirectional link transmits traffic over the given period;
• and
• a channel assigning means that assigns a first channel to the first unidirectional link based on the first average busy time and a second channel to the second unidirectional link based on the second average busy time,
• wherein the channel assigning means comprises:
• a relative link load determining means that divides the link load from the link load measuring means by an average of link loads of all links in a period so as to determine a relative link load of each link for the period, and wherein the period is a time interval of successive channel assignments;
• a link weight determining means that determines, for each link, whether the link has existed in the last t periods, wherein the t is an integer that is larger than 0, for determining a link weight of the link to be 1 if the link has existed in the last t periods, and for determining the link weight of the link based on relative link loads of the link in the last t periods from the relative link load determining means if the link has not existed in the last t periods;
• and
• a channel assigning sub-means for assigning a channel to each link based on the link weight of the link from the link weight determining means, and wherein the link weight determining means comprises:
• a first deciding means that determines, for each link L, the relation between μ(L)−h×σ(L) or μ(L)+h×σ(L) and 1, wherein, μ(L) and σ(L) are a mean value and standard error of relative loads on link L in the last t periods, respectively, and h is an integer that is larger than 0 or equal to 0;
• and
• a first determining means that determines the link weight of the link L to be 1 or μ(L) according to the deciding result of the first deciding means, which determines the link weight of the link L to be μ(L) if the deciding result indicates μ(L)−h×σ(L) >1 or μ(L)+h×σ(L)<1, and determines the link weight of link L to be 1 if the deciding result indicates μ(L)−h×σ(L)≦1 and μ(L)+h×σ(L)≧1.