Invalidity dossier
US 5515379
Time slot allocation method
Current assignee: Motorola Mobility LLC
Added 9/21/2026, 10:32:57 AM
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Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
Patent Overview — US5515379A
Title: Time slot allocation method
Patent number: US5515379A | Application: US08/137,541 | Inventors: Kenneth J. Crisler, Michael L. Needham | Original assignee: Motorola, Inc. | Current assignee (as listed): Motorola Mobility LLC | Priority/filing date: 1993-10-18 | Publication (grant) date: 1996-05-07 | Status: Expired – Lifetime; anticipated expiration 2013-10-18.
Purpose. The invention relates generally to radio communication systems and, in particular, to a method for allocating time slots in a time division multiple access (TDMA) communication system. It addresses inefficiencies in known protocols: slotted ALOHA is described as inefficient (theoretical maximum throughput of roughly thirty-seven percent for single-packet transmissions), while reservation ALOHA, though more efficient for long messages, "inherently introduces lengthy transmission time delays" because one slot per frame is reserved (e.g., four slots at forty-five-millisecond frames requires one hundred eighty milliseconds).
Plain-language scope. A communication unit finds an available time slot (or time slot portion) and transmits a first packet to a time slot allocator. The first packet may contain a single data packet, a request for allocation of n-time slots, or a request to transmit multiple packets. The allocator determines the request type. For an n-time-slot request, it allocates the n-time slots "substantially contiguous in time" when available; for a multiple-packet request, it allocates time slots substantially contiguous in time until the multiple packets have been transmitted. If slots are unavailable, the request is queued. Request packets may occupy only a portion of a slot, so multiple units may submit requests in one slot; access may use slotted-ALOHA, CSMA, or polling.
Source: https://patents.google.com/patent/[US5515379](/patent/US5515379)/en
What the excerpt does not establish. It is an excerpt with text omitted and does not provide the full claims, the complete specification, drawing contents (FIGS. 1–5 are listed but not reproduced), the full prior-art discussion, prosecution history, or the basis for the listed legal status and expiration date. No litigation, ownership-transfer, validity, or prior-art analysis is undertaken here.
Generated 10/1/2026, 10:01:27 PM
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Prior art
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