Adaptive polling technique

• US 4,071,908 A
• Filed: 03/17/1977
• Issued: 01/31/1978
• Est. Priority Date: 03/17/1977
• Status: Expired due to Term

• Current Assignee: Bell Telephone Laboratories, Inc. (Nokia Corporation)
• Original Assignee: Bell Telephone Laboratories, Inc. (Nokia Corporation)
• Inventors: Brophy, Francis Joseph, Hayes, Jeremiah Francis
• Primary Examiner(s): Claffy, Kathleen H.
• Assistant Examiner(s): Chayt, Kenneth A.
• Application Number:
  US05/778,352
• Time in Patent Office: 320 Days
• Field of Search: 364/200, 364/900, 340/147 G, 340/147 LP, 340/147 T, 340/147 R, 178/2 R, 178/2 C, 178/2 D, 178/2 E, 178/3, 178/4.1 B, 179/2 DP, 179/18 FF, 179/18 FG
• US Class Current: 710/46
• CPC Class Codes: G06F 13/22 using successive scanning, e.g. polling G06F13/24 takes precedence
• CPC Class Codes: G06K 7/10039 interrogator driven, i.e. synchronous
• CPC Class Codes: H04L 12/40019 Details regarding a bus master
• CPC Class Codes: H04L 12/403 with centralised control, e.g. polling
• CPC Class Codes: H04Q 9/14 Calling by using pulses

Abstract

Messages are collected by a central polling station from a plurality of remote terminal stations on a multiparty line. The central polling station is arranged to initially query stations in groups, probing successively smaller size subgroups of each group if a station in the group returns an acknowledgement that it has a message and eventually addressing individual stations to collect the messages. In heavily loaded periods, when a large quantity of messages are available at the terminals, the polling station initially queries a smaller size subgroup (or in the extreme, initially addresses individual stations) while in lightly loaded periods, when few or no messages are available, the polling station initially queries a larger size group (or in the extreme, initially broadcasts a query to all of the terminals). Loading of the system is determined by measuring the duration of time required for polling and collecting all the available messages.

Claims

1. A polling system including a control station and a plurality of remote stations, the control station including means for transmitting a sequence of polling words to query the remote stations, polling words designating remote station groups of various sizes and means responsive to responses to the group polling words for sending subsequent polling words in the sequence which designate successively smaller group sizes until individual stations respond, CHARACTERIZED IN THAT

the control station further includes means responsive to the quantity of the responses in a sequence for calculating which one of the various group sizes is to be designated by the initial polling word of a subsequent sequence.

2. A polling system, in accordance with claim 1, wherein the quantity of the responses in a sequence is determined by means for measuring the duration of time required to complete the sequence.

3. A polling system, in accordance with claim 2, wherein the calculating means includes means for designating the subsequent initial group size as inversely related to the measured duration of time.

4. A polling system, in accordance with claim 3, wherein the calculating means includes means for designating all the remote stations as the largest group size and individual remote stations as the smallest group size.

5. A polling system, in accordance with claim 3, wherein the remote stations are arranged in groups and subgroups and the calculating means includes means for designating group and subgroup sizes.

6. A system for collecting messages from a plurality of remote stations including a control station having means for sending initial queries to remote stations in groups and means responsive to acknowledgements to the initial queries for sending queries to successively smaller group sizes until the messages are collected, CHARACTERIZED IN THAT

the control station further includes means responsive to the quantity of collected messages for determining the group size to be queried in a subsequent initial query.

7. A system for collecting messages in accordance with claim 6 wherein the quantity of messages collected is calculated by means for measuring the duration of time required to query the remote stations until the messages are collected.

8. A system for collecting messages, in accordance with claim 7, wherein the determining means includes means for designating the group size to be inversely related to the measured duration of time.

9. A system for collecting messages, in accordance with claim 8, wherein the determining means includes means for designating all the remote stations as the largest group size and individual remote stations as the smallest group size.

10. A system for collecting messages, in accordance with claim 8, wherein the remote stations are arranged in groups and subgroups and the determining means includes means for designating group and subgroup sizes.

11. In a polling system, a plurality of remote stations arranged in groups, each individual station having means responsive to a query addressed individually thereto for sending a message and means responsive to a query addressed to the group thereof for sending an acknowledgement indicating the presence of a message thereat, a control station for sending a sequence of queries to collect messages from the remote stations including means responsive to an acknowledgement to a group query for sending queries addressed to individual stations in the group and means responsive to the quantity of messages collected for alternatively selecting a group query or an individual query as the initial query of the next sequence.

12. In a polling system, in accordance with claim 11, wherein the selecting means includes means for measuring the duration of the sequence to determine the quantity of messages collected.

13. In a polling system, in accordance with claim 12, wherein the selecting means includes means responsive to a measured duration exceeding a predetermined threshold for limiting the next sequence to the sending of individual queries.