Address acquisition

A communications network comprising:

• a subnetwork;
• a first node and a second node, the first node being able to send a network address request to the second node without an interface identifier;
• an entity comprising information on network addresses within the subnetwork, the entity being able to create a link with a link identifier unique within the subnetwork between the first node and the second node and to determine a network address for the first node on the basis of the link identifier;
• wherein the entity is able to check whether the determined network address is unique and to accept the network address if the determined network address is unique.

A mobile terminal to operate with a communications network, the communications network comprising:

• a subnetwork;
• a node;
• an entity comprising information on network addresses within the subnetwork, the entity being able to create a link with a link identifier unique within the subnetwork between the mobile terminal and the node and to determine a network address for the mobile terminal on the basis of the link identifier, and the entity being able to check whether the determined network address is unique and to accept the network address if the determined network address is unique;
• and
• wherein the mobile terminal is able to send a network address request to the node without the interface identifier.

A network element adapted to operate in a communications network, the communications network comprising:

• a subnetwork;
• a node;
• the network element being associated with an entity comprising information on network addresses within the subnetwork, the entity being able to create a link with a link identifier unique within the subnetwork between the node and the network element and to determine a network address for the node on the basis of the link identifier, and the network element being able to receive a network address request from the node without the interface identifier;
• and
• wherein the entity is able to check whether the determined network address is unique and to accept the network address if the determined network address is unique.

A method of a node acquiring an IP network address in a communications system, the method comprising the steps of:

• the node sending a network address request to a gateway over a wireless link requesting a unique interface identifier wherein the network address request does not contain an interface identifier;
• the node receiving from the gateway a unique interface identifier;
• the node adopting the interface identifier;
• the node receiving a network prefix from the gateway;
• and
• the node combining the interface identifier and the network prefix to produce the IP network address.

A method of a gateway assigning an IP network address in a communications system, the method comprising the steps of:

• the gateway receiving a network address request from a node over a wireless link requesting a unique interface identifier wherein the network address request does not contain an interface identifier;
• the gateway sending to the node a unique interface identifier for adoption by the node;
• and
• the gateway sending a network prefix to the node to enable the node to combine the interface identifier and the network prefix to produce the IP network address.