초록 ▼

Domains are defined to incorporate a subnet including a plurality of base stations and routers. Base stations are used by mobile devices to attach to the wired portion of a packet-based network, such as the Internet, and exchange packets thereover with a correspondent node. Local mobility between do

Domains are defined to incorporate a subnet including a plurality of base stations and routers. Base stations are used by mobile devices to attach to the wired portion of a packet-based network, such as the Internet, and exchange packets thereover with a correspondent node. Local mobility between domain base stations is provided by including and updating routing table entries at domain routers and base stations for forwarding packets having a mobile device's address as a destination address to the mobile device. Packets are delivered to the mobile device regardless of the domain base station to which the mobile device is attached. When a mobile device is attached to a base station included within a foreign domain, a care-of address is assigned, and packets are tunneled for delivery of packets to the mobile device. Only one care-of address is required per mobile device per foreign domain. Routing table entries used for packet delivery are updated on a purely local subnet basis within domains, whether home domain or foreign domain, making handoffs between base stations substantially transparent to the home agent and the correspondent node.

대표청구항 ▼

Domains are defined to incorporate a subnet including a plurality of base stations and routers. Base stations are used by mobile devices to attach to the wired portion of a packet-based network, such as the Internet, and exchange packets thereover with a correspondent node. Local mobility between do

Domains are defined to incorporate a subnet including a plurality of base stations and routers. Base stations are used by mobile devices to attach to the wired portion of a packet-based network, such as the Internet, and exchange packets thereover with a correspondent node. Local mobility between domain base stations is provided by including and updating routing table entries at domain routers and base stations for forwarding packets having a mobile device's address as a destination address to the mobile device. Packets are delivered to the mobile device regardless of the domain base station to which the mobile device is attached. When a mobile device is attached to a base station included within a foreign domain, a care-of address is assigned, and packets are tunneled for delivery of packets to the mobile device. Only one care-of address is required per mobile device per foreign domain. Routing table entries used for packet delivery are updated on a purely local subnet basis within domains, whether home domain or foreign domain, making handoffs between base stations substantially transparent to the home agent and the correspondent node. ccording to claim 2, characterized in that the time domain signal of the synchronization burst is precomputed and stored in a memory. 4. An OFDM transmitter, comprising: a unit for mapping the symbols of a predefined symbol sequence according to a predefined mapping scheme on subcarriers of the OFDM system, wherein the symbols of the predefined symbol sequence represent subcarriers of the OFDM system with non-zero-amplitude, and a unit for generating a synchronization burst by Inverse Fourier Transforming the subcarriers of the OFDM system mapped with the symbols of said predefined symbol sequence, characterized in that the mapping unit is designed to modulate the subcarriers such that the envelope fluctuation of the time domain signal of the synchronization burst is minimized by using the following predefined symbol sequence: A -A A -A -A A -A -A A A A A A being a complex value. 5. An OFDM transmitter according to claim 4, characterized by a time extension unit copying the burst part to achieve a periodic nature of the time domain signal. 6. An OFDM transmitter according to claim 4, characterized by a processing unit for precomputing the time domain signal of the synchronization burst and a memory for storing the precomputed time domain signal of the synchronization burst. 7. A mobile communications device, comprising a transmitter according to claim 4. 8. A synchronization burst signal for synchronizing OFDM systems generated by a method according to claim 1.