Title:
【発明の名称】同報システムにおいて同期を維持する方法および装置
Document Type and Number:
Japanese Patent JPH06509458
Kind Code:
A
Abstract:
A simulcast system (FIG. 16) capable of synchronizing and maintaining synchronization of a plurality of base sites (1602, 1604, 1606, 1608) is coupled to a transmitter controller (226). The plurality of base sites (1602, 1604, 1606, 1608) is capable of transmitting data as radio frequency transmission at substantially the same time. A generator (1808) generates time marks (1708) at a predetermined time period (T). A data divider (1812) divides data into predetermined packets to be interposed between at least a pair of time marks. The data packets (1704) and time marks (1708) are transmitted to the plurality of base sites (1602, 1604, 1606, 1608). The plurality of base sites (1602, 1604, 1606, 1608) includes base site receivers (1603, 1605, 1607, 1607) for receiving the data packets (1704) and time marks (1708) and clocks (1611, 1613, 1615, 1617) for measuring the time (T) between each pair of time marks. Base sites controller (1612, 1614, 1616, 1618) determine when there are variations in time between any pair of time marks and the predetermined time period (T). Timers adjust the delay time at each of the plurality of base sites (1602, 1604, 1606, 1608) in response to variation in time between time marks at the corresponding base site, and delay retransmission of data from the receipt of a start command (1706) by a predetermined delay time determined for each of the plurality of base sites to enable the retransmission of data at substantially the same time by the plurality of base sites (1602, 1604, 1606, 1608).
Inventors:
GOLDBERG STEVEN JEFFREY (US)
Application Number:
JP50068993A
Publication Date:
October 20, 1994
Filing Date:
May 25, 1993
Export Citation:
Assignee:
MOTOROLA INC (US)
International Classes:
H04H20/67; H04J3/06; H04W92/00; H04L7/00; H04L7/033; H04W56/00; (IPC1-7): H04B7/26; H04L7/00
Attorney, Agent or Firm:
Shinsuke Onuki (1 person outside)