The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 18, 1994
Filed:
Dec. 12, 1991
Harald Kallin, Sollentuna, SE;
Anna Fallgren, Stockholm, SE;
Telefonaktiebolaget L M Ericsson, Stockholm, SE;
Abstract
A cellular mobile radiotelephone system listens for call accesses on a control channel of an umbrella cell and on a control channel of a microcell located within said umbrella cell and responds to the call access only on the control channel of the umbrella cell. More particularly, the microcells within a particular umbrella cell are provided with listen-only control channel at the same frequency as the uplink control channel of the umbrella cell. An umbrella cell and one or several of its microcells may therefore each receive the same call accesses. During call access, the umbrella cell and each of the microcells determines the strength of the received signal and forwards this information to the system. The system selects the most appropriate cell out of the umbrella cell and the microcells to handle the call and causes the umbrella cell to respond to the call access on its downlink control channel. Among the umbrella cell and its microcells, there are therefore a plurality of uplink control channels, one for each defined cell, and a single downlink control channel, namely that of the umbrella cell. Cell planning remains unchanged as does a directed retry mechanism. Because there is only a single downlink control channel within the coverage area of an umbrella cell, excessive rescanning is avoided. Furthermore, a call is established at the outset in the most appropriate cell, using resources more efficiently and avoiding congestion in the umbrella cell.