Method and apparatus for cell reselection
A method and wireless transmit receive unit (WTRU) are disclosed that is configured to perform cell reselection to another cell when the WTRU is in a CELL_FACH state using an Enhanced-Dedicated Channel (E-DCH). The cell reselection is based on internal measurements by the WTRU. Alternatively, the cell reselection can be WTRU based on the WTRU measurements reported to the network.
1. A method of operating a wireless network to communicate with a wireless transmit/receive unit (WTRU), the method comprising:
receiving, via a base station, a cell update message sent from the WTRU, the cell update message including an indication that the WTRU supports communications over an Enhanced Dedicated Channel (E-DCH) in a CELL_FACH state, wherein the WTRU has an assigned enhanced radio network temporary identifier (E-RNTI);
transmitting, via the base station, a cell update confirm message to the WTRU, cell update confirm message including a new assigned E-RNTI;
receiving an E-DCH transmission from the WTRU when the WTRU is in the CELL_FACH state and after the WTRU has received the new assigned E-RNTI,
wherein when the WTRU is in the CELL_FACH state, the WTRU performs cell reselection except during the E-DCH transmission.
2. The method of claim 1 , wherein the cell update message includes a cell enhanced radio network temporary identifier (C-RNTI) and a high speed downlink shared channel (HS-DSCH) enhanced radio network temporary identifier (H-RNTI).
3. The method of claim 1 , further comprising:
receiving a preamble transmission from the WTRU; and
in response to the received preamble transmission, providing to the WTRU an indication of resources for the E-DCH transmission.
4. A wireless communication system comprising a base station and a wireless transmit/receive unit (WTRU), the base station comprising:
a receiver; and
a transmitter;
wherein the receiver receives a cell update message sent from the WTRU, the cell update message including an indication that the WTRU supports communications over an Enhanced Dedicated Channel (E-DCH) while the WTRU is in a CELL_FACH state, wherein the WTRU has an assigned enhanced radio network temporary identifier (E-RNTI),
wherein the transmitter transmits, to the WTRU, a cell update confirm message, the cell update confirm message including a new assigned,
wherein the receiver receives an E-DCH transmission from the WTRU when the WTRU is in the CELL_FACH state and after the WTRU has received the new assigned E-RNTI, and
wherein when the WTRU is in the CELL_FACH state, the WTRU performs cell reselection except during the E-DCH transmission.
5. The wireless communication system of claim 4 , wherein the cell update message includes a cell enhanced radio network temporary identifier (C-RNTI) and a high speed downlink shared channel (HS-DSCH) enhanced radio network temporary identifier (H-RNTI).
6. The wireless communication system of claim 4 , wherein the receiver:
further receives a preamble transmission from the WTRU and in response to the received preamble transmission, provides to the WTRU an indication of resources for the E-DCH transmission.
7. The wireless communication system of claim 4 , wherein the base station is one of a Node-B, an access point, a site controller, and an interfacing device.
8. A method of providing a wireless communication system, the method comprising:
providing a wireless transmit/receive unit (WTRU) configured to perform cell reselection when the WTRU is in a CELL_FACH state except during an E-DCH transmission by the WTRU; and
operating a base station to
transmit, to the WTRU, an enhanced radio network temporary identifier (E-RNTI) for the WTRU,
process a cell update message received from the WTRU, the cell update message including an indication that the WTRU supports communications over an Enhanced Dedicated Channel (E-DCH) while the WTRU is in the CELL_FACH state,
in response to the cell update message, provide to the WTRU a cell update confirm message that includes a new E-RNTI for the WTRU; and
receives an E-DCH transmission from the WTRU when the WTRU is in the CELL_FACH state and after the WTRU has received the new E-RNTI.
9. The method of claim 8 , wherein the cell update message includes a cell enhanced radio network temporary identifier (C-RNTI) and a high speed downlink shared channel (HS-DSCH) enhanced radio network temporary identifier (H-RNTI).
10. The method of claim 8 , further comprising operating the base station to:
receive a preamble transmission from the WTRU; and
in response to the received preamble transmission, provide to the WTRU an indication of resources for the E-DCH transmission.