Method and apparatus for predictive QoS routing for broad band low earth satellite networks

A method for predictive QoS routing of calls within a satellite constellation orbiting the earth, said satellite constellation including at least one orbit, with each one of the at least one orbit including a plurality S of satellites, each indexed by a number s, and communicatively connected by a plurality of communication links, with each particular satellite having a satellite-fixed cell divided, perpendicularly with respect to the orbit of the particular satellite, into a plurality L of satellite-fixed cell slots, with the movement of the plurality S of satellites over the earth being characterized in that the satellite-fixed cell for a satellite indexed at s covers the same area as the satellite-fixed cell of a satellite indexed at s+1 after passing over an area on the earth equivalent to the area of L satellite-fixed cell slots, and with an offset satellite-fixed cell being defined each time the satellite-fixed cell covers the area of one of L satellite-fixed cell slots while moving between the position of the satellite-fixed cell corresponding to a satellite indexed s and the satellite-fixed cell corresponding to a satellite indexed s+1, providing L offset satellite-fixed cells with the L offset satellite-fixed cells for each particular satellite being indexed by a number l=1, . . . , L, with the satellite-fixed cells and the offset satellite-fixed cells being defined as reference satellite-fixed cells, said method including the steps of:

• a. receiving a call from a source user to a destination user;
• b. acquiring information for the source user and the destination user, including a user address and user location;
• c. determining the satellite, the satellite-fixed cell, and the satellite-fixed cell slot within the satellite-fixed cell in which the source user is located, said satellite being defined as the source user end-reference satellite;
• d. determining the satellite, the satellite-fixed cell, and the satellite-fixed cell slot within the satellite-fixed cell in which the destination user is located, said satellite being defined as the destination user end-reference satellite;
• e. determining all paths including at most a predetermined number J of inter-satellite hops, between the source user end-reference satellite and the destination end-user reference satellite;
• f. calculating the minimum residual link capacity for each of the paths determined in step (e);
• g. determining, for each offset satellite-fixed cell l=1, . . . ,L, a set {kl} of paths that maximize the residual bandwidth at that offset satellite-fixed cell;
• and
• h. picking, from each set {kl} of paths determined for each offset satellite-fixed cell, one path p such that the combined set CS of paths for all of the offset satellite-fixed cells minimizes the number of communication link changes necessary to maintain a call between the source user and the end user.

An apparatus for predictive QoS routing of calls within a satellite network including:

• a. a satellite constellation orbiting the earth, said satellite constellation including at least one orbit, with each one of the at least one orbit including a plurality S of satellites, each indexed by a number s, and communicatively connected by a plurality of communication links, with each particular satellite having a satellite-fixed cell divided, perpendicularly with respect to the orbit of the particular satellite, into a plurality L of satellite-fixed cell slots, with the movement of the plurality S of satellites over the earth being characterized in that the satellite-fixed cell for a satellite indexed at s covers the same area as the satellite-fixed cell of a satellite indexed at s+1 after passing over an area on the earth equivalent to the area of L satellite-fixed cell slots, and with an offset satellite-fixed cell being defined each time the satellite-fixed cell covers the area of one of L satellite-fixed cell slots while moving between the position of the satellite-fixed cell corresponding to a satellite indexed s and the satellite-fixed cell corresponding to a satellite indexed s+1, providing L offset satellite-fixed cells with the L offset satellite-fixed cells for each particular satellite being indexed by a number l=1, . . . , L, with the satellite-fixed cells and the offset satellite-fixed cells being defined as reference satellite-fixed cells;
• b. means for receiving a call from a source user to a destination user;
• c. means for acquiring information for the source user and the destination user, including a user address and user location;
• d. means for determining the satellite, the satellite-fixed cell, and the satellite-fixed cell slot within the satellite-fixed cell in which the source user is located, said satellite being defined as the source user end-reference satellite;
• e. means for determining the satellite, the satellite-fixed cell, and the satellite-fixed cell slot within the satellite-fixed cell in which the destination user is located, said satellite being defined as the destination user end-reference satellite;
• f. means for determining all paths including at most a predetermined number J of inter-satellite hops, between the source user end-reference satellite and the destination end-user reference satellite;
• g. means for calculating the minimum residual link capacity for each of the paths determined by the means in (f);
• h. means for determining, for each offset satellite-fixed cell l=1, . . . ,L, a set {kl} of paths that maximize the residual bandwidth at that offset satellite-fixed cell;
• and
• i. means for picking, from each set {kl} of paths determined for each offset satellite-fixed cell, one path p such that the combined set CS of paths for all of the offset satellite-fixed cells minimizes the number of communication link changes necessary to maintain a call between the source user and the end user.

An apparatus for predictive QoS routing of calls within a satellite constellation orbiting the earth, said satellite constellation including at least one orbit, with each one of the at least one orbit including a plurality S of satellites, each indexed by a number s, and communicatively connected by a plurality of communication links, with each particular satellite having a satellite-fixed cell divided, perpendicularly with respect to the orbit of the particular satellite, into a plurality L of satellite-fixed cell slots, with the movement of the plurality S of satellites over the each being characterized in that the satellite-fixed cell for a satellite indexed at s covers the same area as the satellite-fixed cell of a satellite indexed at s+1 after passing over an area on the earth equivalent to the area of L satellite-fixed cell slots, and with an offset satellite-fixed cell being defined each time the satellite-fixed cell covers the area of one of L satellite-fixed cell slots while moving between the position of the satellite-fixed cell corresponding to a satellite indexed s and the satellite-fixed cell corresponding to a satellite indexed s+1, providing L offset satellite-fixed cells with the L offset satellite-fixed cells for each particular satellite being indexed by a number l=1, . . . , L, with the satellite-fixed cells and the offset satellite-fixed cells being defined as reference satellite-fixed cells, said apparatus including:

• a. means for receiving a call from a source user to a destination user;
• b. means for acquiring information for the source user and the destination user, including a user address and user location;
• c. means for determining the satellite, the satellite-fixed cell, and the satellite-fixed cell slot within the satellite-fixed cell in which the source user is located, said satellite being defined as the source user end-reference satellite;
• d. means for determining the satellite, the satellite-fixed cell, and the satellite-fixed cell slot within the satellite-fixed cell in which the destination user is located, said satellite being defined as the destination user end-reference satellite;
• e. means for determining all paths including at most a predetermined number J of inter-satellite hops, between the source user end-reference satellite and the destination end-user reference satellite;
• f. means for calculating the minimum residual link capacity for each of the paths determined by the means of (e);
• g. means for determining, for each offset satellite-fixed cell l=1, . . . ,L, a set {kl} of paths that maximize the residual bandwidth at that offset satellite-fixed cell;
• and
• h. means for picking, from each set {kl} of paths determined for each offset satellite-fixed cell, one path p such that the combined set CS of paths for all of the offset satellite-fixed cells minimizes the number of communication link changes necessary to maintain a call between the source user and the end user.