Fallback procedures for two-step random access procedures

US11432324B2 · kind B2 · utility

Assignee

• QUALCOMM Incorporated · US

Inventors

• Jing Lei · San Diego, US
• Linhai HE · San Diego, US
• Hung Dinh LY · San Diego, US
• Seyong Park · San Diego, US
• Naga Bhushan · San Diego, US
• Ying Wang · Taichung, TW
• Wanshi Chen · San Diego, US
• Joseph Binamira Soriaga · San Diego, US

Key dates

• Filing date: Jan 31, 2020
• Grant date: Aug 30, 2022
• Expiry date: Aug 20, 2040

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04W74/0838
• WIPO field: Digital communication
• WIPO sector: Electrical engineering

Abstract

Fallback procedures for user equipments (UEs) are described that provide efficient fallback to a four-step random access procedure from a two-step random access procedure. For example, after transmitting a first message of a two-step random access procedure, a UE may start a fallback timer or counter and monitor for a second message of the two-step random access procedure for the duration of the fallback timer or counter. At the expiration of the fallback timer or counter, the UE may fall back to a four-step random access procedure. In some cases, the UE may transmit multiple repetitions of the first message and monitor for responses after transmitting the repetitions or after each repetition. Additionally or alternatively, the base station may transmit an explicit signal to the UE that may signal to the UE to perform a fallback procedure at a beginning or middle of a random access procedure.