Maintaining prefix consistency in dynamic moving networks

A first mobile router, MR, connectable to a first moving network associated to a home agent, HA, the first moving network comprising at least a second MR, wherein each of the MRs is adapted to have a relation with said HA and to be assigned a first set of network prefixes identifying the first moving network, the first MR comprising:

• means for determining if the first moving network is split into a second and a third moving network such that the first MR belongs to the second moving network,
• means for transmitting a request to said HA to be re-assigned the first set of network prefixes if it is determined that the first moving network is split into a second and a third moving network,
• means for being re-assigned the first set of network prefixes if it is determined that the first moving network is split into a second and a third moving network and if local connectivity between the first MR and all other MRs that are assigned the first set of network prefixes is verified,
• means for switching to a second set of network prefixes if it is determined that the first moving network is split into a second and a third moving network and if local connectivity between the first MR and all other MRs that are assigned the first set of network prefixes is not verified;
• means for waiting a time period after determining that the first moving network has been split before transmitting a request to said HA to be re-assigned the first set of network prefixes and
• means for selecting the length of said time period based on a value associated with the second moving network, such that a higher value results in a longer time period than a smaller value, wherein the value is a measure of the consequences of changing the set of network prefixes such that a greater value is an indication of a greater consequence of a prefix change.

A method in a first mobile router, MR, connectable to a first moving network associated to a home agent, HA, the first moving network comprising at least a second MR, wherein each of the MRs is adapted to have a relation with said HA and to be assigned a first set of network prefixes identifying the first moving network, the method comprising the steps of:

• determining if the first moving network is split into a second and a third moving network such that the first MR belongs to the second moving network,
• transmitting a request to said HA to be re-assigned the first set of network prefixes if it is determined that the first moving network is split into a second and a third moving network, and
• being re-assigned the first set of network prefixes if it is determined that the first moving network is split into a second and a third moving network and if local connectivity between the first MR and all other MRs that are assigned the first set of network prefixes can be verified,
• switching to a second set of network prefixes if it is determined that the first moving network is split into a second and a third moving network and if local connectivity between the first MR and all other MRs that are assigned the first set of network prefixes is not verified;
• waiting a time period after determining that the first moving network has been split before transmitting a request to said HA to be re-assigned the first set of network prefixes:
• and
• selecting the length of said time period based on the number of nodes in the second moving network, such that a greater number of nodes results in a longer time period than a smaller number of nodes.

A method in a first mobile router, MR, connectable to a first moving network associated to a home agent, HA, the first moving network comprising at least a second MR, wherein each of the MRs is adapted to have a relation with said HA and to be assigned a first set of network prefixes identifying the first moving network, the method comprising the steps of:

• determining if the first moving network is split into a second and a third moving network such that the first MR belongs to the second moving network,
• transmitting a request to said HA to be re-assigned the first set of network prefixes if it is determined that the first moving network is split into a second and a third moving network, and
• being re-assigned the first set of network prefixes if it is determined that the first moving network is split into a second and a third moving network and if local connectivity between the first MR and all other MRs that are assigned the first set of network prefixes can be verified,
• switching to a second set of network prefixes if it is determined that the first moving network is split into a second and a third moving network and if local connectivity between the first MR and all other MRs that are assigned the first set of network prefixes is not verified,
• waiting a time period after determining that the first moving network has been split before transmitting a request to said HA to be re-assigned the first set of network prefixes and
• selecting the length of said time period based on a value associated with the second moving network, such that a higher value results in a longer time period than a smaller value, wherein the value is a measure of the consequences of changing the set of network prefixes such that a greater value is an indication of a greater consequence of a prefix change.