Remote level measurement system for use in a multi-terminal communications system

• US 4,648,123 A
• Filed: 01/08/1985
• Issued: 03/03/1987
• Est. Priority Date: 11/29/1982
• Status: Expired due to Fees

• Current Assignee: C-Cor Labs Incorporated
• Original Assignee: C-Cor Labs Incorporated
• Inventors: Schrock, Clifford B.
• Primary Examiner(s): Ng, Jin F.
• Application Number:
  US06/690,394
• Time in Patent Office: 784 Days
• Field of Search: 455/2-6, 455/67, 455/68, 455/69, 358/84, 358/86, 340/825.06, 340/825.3, 340/825.54, 179/170 F, 179/170.8
• US Class Current: 455/67.14
• CPC Class Codes: H04L 12/2801 Broadband local area networks

Abstract

A remote level measurement system for use in a multi-terminal communications system wherein a plurality of remote terminals are connected to a master terminal by a distribution network for bi-directional transmission of signals. The remote terminals are adapted to receive and transmit signals on the network. work. The master terminal is adapted to transmit an interrogation signal to a selected remote terminal and wait for a period of time sufficient for the interrogation signal to be transmitted to, and detected by, a selected remote terminal and a reply signal to be sent back to the master terminal by the remote terminal. At the expiration of that time the master terminal samples and measures the analog level of the reply signal.

Claims

1. A remote terminal level measurement system for use in a multi-terminal communications system for bi-directional transmission of signals over a communications network having a head end for transmitting outgoing signals and receiving reply signals from a plurality of remote terminals, comprising:

(a) identifier means at said head end for identifying outgoing signals each associated with a specific remote terminal;

(b) reply means at each remote terminal and responsive to said outgoing signals from said head end, for identifying an outgoing signal associated with its respective remote terminal and transmitting a reply signal to said head end;

(c) timer means at said head end for determining the period of time that should pass following the identification of an outgoing signal by said identifier means after which a reply signal from a specific remote terminal will be received at said head end;

(d) measurement means at said head end and responsive to said timer means, for measuring at said head end the analog reply signal level at the end of said period of time; and

(e) memory means at said head end for storing the measurement of said reply signal level for access at a later time.

2. The measurement system of claim 1 wherein said measurement means includes sample and hold circuit means for sampling the analog level of said reply signal and holding the sampled level until cleared.

3. A method for measurement of the transmission output level of a remote terminal in a communications system in which a plurality of remote terminals are connected through a head end to a master terminal by a communications network for bi-directional transmission of signals between said master terminal and said remote terminals, the method comprising the steps of:

(a) identifying at said head end outgoing signals transmitted by said master terminal, each associated with a specific remote terminal;

(b) at the head end, determining a predetermined time period following the identification of said outgoing signal, corresponding to the time required for a reply signal from said specific remote terminal to be received at said head end;

(c) in response to the end of said predetermined time period, measuring at said head end the analog level of said reply signal; and

(d) storing the measurement of the level of said reply signal for access at a later time.