Invalidity dossier
US 5594738
Time slot allocation method
Current assignee: Motorola Mobility LLC
Added 9/21/2026, 9:27:17 AM
Active provider: DeepSeek · deepseek-flash
Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
Patent Overview: US5594738A — Time Slot Allocation Method
Title: Time Slot Allocation Method
Patent Number: US5594738A
Inventors: Kenneth J. Crisler; Michael L. Needham
Original Assignee: Motorola, Inc. (current assignee listed as Motorola Mobility LLC)
Priority Date: 1993-10-18 (claimed from US08/137,541)
Filing Date: 1995-06-23 (application US08/494,618)
Publication/Grant Date: 1997-01-14
Legal Status: Expired – Lifetime (anticipated expiration 2013-10-18)
Purpose
The invention relates to radio communication systems and addresses a method for allocating time slots in a time division multiple access (TDMA) communication system. It aims to improve on known protocols (slotted ALOHA and reservation ALOHA). The patent notes slotted ALOHA's theoretical maximum throughput is roughly 37%, and reservation ALOHA introduces lengthy transmission delays because a multi-slot message takes as many uplink time frames as time slots (e.g., four slots over three hundred milliseconds).
Plain-Language Scope
A communication unit sends a first packet to a time slot allocator in an available uplink time slot. The first packet may request allocation of N uplink time slots or request to transmit multiple packets. The allocator determines the request type. For N requested slots, it allocates N uplink time slots substantially contiguous in time when available, then transmits an allocation indication in each of N corresponding downlink time slots to confirm each allocated uplink time slot. For multiple packets, it likewise allocates uplink time slots substantially contiguous in time until the packets are transmitted, confirming each via corresponding downlink time slots. Per the described system, uplink slots are slightly delayed relative to corresponding downlink slots, allowing units to read the slot descriptor block (SDB) before transmitting.
Source: https://patents.google.com/patent/[US5594738](/patent/US5594738)/en
Not Established by the Excerpt
The supplied text does not establish the full claims, the complete written description, all drawing details, or the exact boundaries of the "time slot portions." It does not establish actual measured performance, litigation history, validity, or a complete prior-art analysis. Only illustrative throughput and delay figures are given; these are not verified results. The excerpt also does not confirm ownership status beyond listed reassignments.
Generated 10/1/2026, 10:02:20 PM
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Litigation summary
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PTAB challenges
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Assignment history
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Prior art
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Obviousness
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Extensions
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Derivative works
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