Wireless communication in an elevator
A data communication arrangement for elevators is disclosed. In the arrangement a directional antenna is used for transmitting data from elevator car. Correspondingly, the counterpart antenna in the end of the elevator shaft is transmitting with a directional antenna. In the elevator a further omnidirectional antenna is used to communicate with the terminal devices belonging to passengers. The properties of antennas may be adjusted based on the speed and location of the elevator car. In addition to the properties of antennas also other transmission characteristics may be adjusted based on the same information.
1. A method for providing a local area wireless network in an elevator car comprising:
communicating with at least one terminal device using a wireless local area network connection by using at least one wireless base station in said elevator car;
transceiving said communication between said at least one terminal device and said at least one wireless base station by using a directional antenna at the elevator with a transceiver located in an end of a shaft of the elevator opposing the directional antenna;
determining a plurality of destination floors for the elevator car;
predetermining when to switch between the directional antenna and an omnidirectional antenna at the elevator,
wherein the omnidirectional antenna communicates with a transceiver located in a vicinity of one of the plurality of destination floors;
switching said transceiving from said directional antenna to the omnidirectional antenna communicating with the transceiver located in the vicinity of a particular destination floor of the plurality of destination floors where the elevator car stops; and
switching said transceiving back to said directional antenna after the elevator car starts moving again from the particular destination floor.
2. The method according to claim 1 , wherein said switching is performed by adjusting transmission properties of the antenna that is being used for said transceiving.
3. The method according to claim 1 , wherein said communication is arranged through a plurality of base stations arranged in a mesh network.
4. The method according to claim 1 , wherein the method further comprises:
determining the speed of the elevator car; and
choosing the data transmission speed according said speed of the elevator car.
5. The method of claim 1 , wherein, when the elevator car stops on a particular destination floor, the method further comprises:
determining a distance between said omnidirectional antenna located on the elevator car and said transceiver located in the vicinity of the stopping location on one of the plurality of destination floors; and
adjusting transmitting properties in said transceiving according to said determined distance.
6. The method according to claim 5 , wherein adjusting at least one of the following properties: transmission power, directivity of the antenna, direction of the transmission, location of the source of the transmission and data transfer rate.
7. The method of claim 1 , wherein prior to the elevator car starting to move, predetermining when to switch between the directional antenna and the omnidirectional antenna at the elevator further comprises:
predetermining to switch said transceiving from said directional antenna to an the omnidirectional antenna communicating with a transceiver located in a vicinity of a first anticipated stopping location of the elevator car on one of the plurality of destination floors based on the first anticipated stopping location of the elevator car; and
predetermining whether to switch said transceiving back to said directional antenna after the elevator car reaches the first anticipated stopping location and after the elevator car starting to move again based on a second anticipated stopping location of the elevator car; and
storing the of predetermination of switching of said transceiving based on the first anticipated stopping location of the elevator car and on the second anticipated stopping location of the elevator car.
8. A system for providing a local area wireless network in an elevator car, which system further comprises:
at least one wireless local area base station configured to communicate with at least one terminal device in said elevator car; and
a directional antenna configured to transceive said communication between said at least one terminal device and said at least one wireless base station by using the directional antenna at the elevator with a transceiver located in an end of a shaft of the elevator opposing the directional antenna,
an elevator controlling system; and
a controller configured to
adjust transmitting properties,
determine a plurality of destination floors for the elevator car,
predetermine when to switch between the directional antenna and an omnidirectional antenna at the elevator,
wherein the omnidirectional antenna communicates with a transceiver located in a vicinity of one of the plurality of destination floors;
switch said transceiving from said directional antenna to the omnidirectional antenna communicating with the transceiver located in the vicinity of a particular destination floor of the plurality floors where the elevator car stops; and
switching said transceiving back to said directional antenna after the elevator car starts moving again from the particular destination floor.
9. The system according to claim 8 , wherein the controller is further configured to perform said switching by adjusting transmission properties of the antenna that is being used for said transceiving.
10. The system according to claim 8 , wherein said communication is arranged through a plurality of base stations arranged in a mesh network.
11. The system according to claim 8 , wherein said controller is configured to adjust at least one of the following properties: transmission power, directivity of the antenna, direction of the transmission, location of the source of the transmission and data transfer rate.
12. The system according to claim 8 wherein prior to the elevator car starting to move, predetermining when to switch the directional antenna and the omnidirectional antenna at the elevator further comprises:
predetermining to switch said transceiving from said directional antenna to an omnidirectional antenna communicating with a transceiver located in a vicinity of a first anticipated stopping location of the elevator car on one of the plurality of destination floors based on the first anticipated stopping location of the elevator car;
predetermining whether to switch said transceiving back to said directional antenna after the elevator car reaches the first anticipated stopping location and prior to the elevator starting to move again based on a second anticipated stopping location of the elevator car; and
storing the predetermination of switching of said transceiving based on the first anticipated stopping location of the elevator car and the second anticipated stopping location of the elevator car.