Patents Assigned to Portaphone AG
  • Patent number: 4467141
    Abstract: A mobile subscriber station served by a telephone network is coupled by a radio link with an individually associated stationary relay station directly connected to that network. The tow stations are able to communicate with each other, over a radius of about 50 meters, on any of 40 channels available to all the posts of subscriber and relay stations in the neighborhood. Each station of a post includes a transmitter and a receiver operating at about 900 MHz; in the idle state of the post, the receivers of both stations continuously scan the available channels to determine their free or busy condition. A person wishing to make an outgoing call causes the transmitter of the subscriber station to send out a predetermined code word which is picked up by the receiver of the associated relay station in its scanning operation and, upon verification by a code comparator, initiates the emission of a handshake signal to the subscriber station whereupon the channel is seized to let the call proceed over the network.
    Type: Grant
    Filed: September 7, 1982
    Date of Patent: August 21, 1984
    Assignee: Portaphone AG
    Inventors: Heinz Resch, Franz Machl, Klaus Kerschbaumer, Helmut Ullrich