 Communication device having multiple displays and method of operating the same |
| OF THE PREFERRED EMBODIMENTS According to the present invention, a portable communication device ... |
|
| Billing records enhanced by called party names from subscriber phone book |
| The inventors of the current invention have realised that conventional billing approaches are ... |
|
| Selective call receiver having a variable frequency vibrator |
| Briefly, according to the invention, a electronic device comprises a receiver for receiving a ... |
|
| Electromagnetic radiation alerting device for use with a cellular telephone |
| The striking deficiencies of existing technologies, outlined above, lead to the inescapable ... |
|
| Foldable portable terminal |
| The invention claimed is: 1. A portable terminal comprising: a first cabinet comprising a display ... |
|
| Scan type display device with image scanning function |
| Therefore, it is an object of the present invention to provide a scan type display device which has ... |
|
| Lighted message fan |
| The present invention provides a method of emitting a lighted visual image in the form of letters, ... |
|
| Electronic audio accessory for use with automotive stereo loudspeakers |
| OF THE INVENTION A preferred embodiment of the invention is now described in detail. Referring to ... |
|
| Hand-held e-mail device |
| The present invention overcomes the problems noted above and satisfies the needs in this field for ... |
|
| Methods and apparatus to increase sound quality of piezoelectric devices |
| Accordingly, an object and advantage of the present invention is to provide a vibrating ... |
|
|
Method for determining execution time of inter-frequency hard handoff and establishing the hard handoff environment
| Details |
Inventors: Kwon, Suk-hyoung; Kim, Wan-soo;
Assignee: Samsung Electronics, Co., Ltd. (KR)
Primary Examiner: Vo; Nguyen T.
Assistant Examiner:
Attorney, Agent or Firm: Dilworth & Barrese, LLP
A method for determining the execution time and handoff direction of a hard handoff by a base station controller in a code division multiple access (CDMA) system. The execution time and handoff direction is determined for a mobile station moving between two base station transceiver having different frequency allocations (Fas). The service region of the CDMA system is divided as individual cells where each cell further comprises one or more sectors (sub-cells). Sub-cells are either common frequency sub-cells or border frequency sub-cells. Common frequency sub-cells are defined as those sub-cells for which the common frequencies of the neighboring sub-cells are all in use. Correspondingly, a border frequency sub-cells defines a sub-cell for which the common frequencies of the neighboring sub-cells are not all in use. The method of the present invention generally comprises the steps of: receiving a pilot strength measurement message (PSMM) from the mobile station by the base station controller (BSC), the PSMM including a plurality of pilot signals each having a pilot signal strength; upon receiving the PSMM by the BSC, determining whether all sub-cells with which the mobile station is currently in communication are border frequency sub-cells; if it least one sub-cell is determined not to be a border frequency sub-cell, executing a general handoff; if all sub-cells are determined to be border frequency sub-cells, periodically ordering the PSMM from all sub-cells with which the mobile station is currently in communication by the BSC; analyzing a received PSMM transmitted from the mobile station in response to the PSMM order issued by the BSC to determine whether the pilot signal strengths received from all sub-cells are lower than a predetermined power level, T_DOWN, and activating a timer set to a predetermined time, T_TDOWN if said pilot signal strengths received from all sub-cells are lower than a predetermined power level; if the timer expires without interruption during the time interval T_TDOWN ordering the mobile station to execute an intra-cell inter-frequency hard handoff to a common frequency that all base transceiver stations service. |
|
DETAILED DESCRIPTION We claim: 1.
A method for determining the execution time of an inter-frequency hard handoff in a mobile telecommunication system divided into a plurality of sectors, said telecommunication system including at least one mobile station providing a subscriber with mobile telecommunication services, a plurality of base transceiver stations (BTSs) each servicing one of said plurality of sectors, each BTS transmitting a unique pilot signal identifying said BTS, and a base station controller managing a sub-cell, the method comprising the steps of: (a) receiving a pilot strength measurement message (PSMM) from the mobile station by the base station controller (BSC), the PSMM including a plurality of pilot signals each having a pilot signal strength; (b) upon receiving the PSMM by the BSC, determining whether all sub-cells with which the mobile station is currently in communication are border frequency sub-cells; (c) if it least one sub-cell is determined not to be a border frequency sub-cell, executing a general handoff; (d) if all sub-cells are determined to be border frequency sub-cells, periodically ordering the PSMM from all sub-cells with which the mobile station is currently in communication by the BSC; (e) analyzing a received PSMM transmitted from the mobile station in response to the PSMM order issued by the BSC to determine whether the pilot signal strengths received from all sub-cells are lower than a predetermined power level, T_DOWN, and activating a timer set to a predetermined time, T_TDOWN if said determination is satisfied; (f) if the timer expires normally ordering the mobile station to execute an intra-cell inter-frequency hard handoff to a common frequency that all base transceiver stations service.
2.
The method as set forth in claim 1, wherein the T_TDOWN power level is set to a power level larger than a handoff drop threshold, T_DROP.
3.
The method as set forth in claim 2, wherein after the step of activating the timer, said method further comprises a step of cancelling the timer and returning to step (d) when it is determined that the received pilot signal strengths of all sub-cells are not less than T_DOWN at step (e)
|
|
Ring Tones 
