Uplink timing adjustment in high speed deployments

An apparatus for a user equipment (UE), the apparatus comprising memory and processing circuitry to configure the UE to:

• switch from a serving remote radio head (RRH) of a serving cell to a neighboring RRH of the serving cell, the serving RRH and the neighboring RRH in a unidirectional high speed train (HST) deployment;
• and
• adjust timing for uplink frequency range 2 (FR2) transmission to the neighboring RRH using a one-shot uplink timing adjustment after switching from the serving RRH to the neighboring RRH,
• determine a value of a difference between an end of a first transmission from the neighboring RRH and an end of reception of the first transmission at the UE (Tp2) less a difference between an end of a second transmission from the serving RRH and an end of reception of the second transmission at the UE (Tp1);
• determine whether the value is greater than a predetermined gradual timing adjustment set by a Third Generation Partnership Project (3GPP) specification;
• and
• apply the one-shot uplink timing adjustment in response to a determination that the value is greater than the predetermined gradual timing adjustment after switching from the serving RRH to the neighboring RRH, the one-shot uplink timing adjustment being twice the value, and
• wherein the memory is configured to store the one-shot uplink timing adjustment.

An apparatus for a 5th generation NodeB (gNB), the apparatus comprising memory and processing circuitry to configure the gNB to:

• receive, from a user equipment (UE), UE capability signaling including an indication whether a one-shot uplink timing adjustment is supported by the UE;
• transmit, to the UE, a network flag to inform the UE that the one-shot uplink timing adjustment is expected from the UE;
• receive, from the UE, first uplink frequency range 2 (FR2) signals transmitted at a serving remote radio head (RRH), the first uplink FR2 signals transmitted at a first timing;
• and
• receive, from the UE, second uplink FR2 signals transmitted at a neighboring RRH after the UE has switched to the neighboring RRH, the serving RRH and the neighboring RRH in a unidirectional high speed train (HST) deployment, the second uplink FR2 signals transmitted at a second timing using the one-shot uplink timing adjustment, and
• wherein:
• the one-shot uplink timing adjustment is applied in response to a determination that a first value is greater than a second value,
• the first value is a difference between an end of a first transmission from the neighboring RRH and an end of reception of the first transmission at the UE (Tp2) less a difference between an end of a second transmission from the serving RRH and an end of reception of the second transmission at the UE (Tp1),
• the second value is one of:
• a predetermined gradual timing adjustment set by a Third Generation Partnership Project (3GPP) specification,
• a first combination of the predetermined gradual timing adjustment plus a timing error limit,
• a second combination of the predetermined gradual timing adjustment plus twice a downlink error, and
• a multiple of the predetermined gradual timing adjustment, and
• the one-shot uplink timing adjustment is twice the first value,
• wherein the memory is configured to store the one-shot uplink timing adjustment.

A non-transitory computer-readable storage medium that stores instructions for execution by one or more processors of a user equipment (UE), the one or more processors to configure the UE to, when the instructions are executed:

• switch from a serving remote radio head (RRH) of a fifth generation (5G) nodeB (gNB) to a neighboring RRH of the gNB, the serving RRH and the neighboring RRH in a unidirectional high speed train (HST) deployment;
• adjust timing for uplink frequency range 2 (FR2) transmission to the neighboring RRH using a one-shot uplink timing adjustment after switching from the serving RRH to the neighboring RRH;
• apply the one-shot uplink timing adjustment in response to a determination that a first value is greater than a second value,
• the first value is a difference between an end of a first transmission from the neighboring RRH and an end of reception of the first transmission at the UE (Tp2) less a difference between an end of a second transmission from the serving RRH and an end of reception of the second transmission at the UE (Tp1),
• the second value is one of:
• a predetermined gradual timing adjustment set by a Third Generation Partnership Project (3GPP) specification,
• a first combination of the predetermined gradual timing adjustment plus a timing error limit,
• a second combination of the predetermined gradual timing adjustment plus twice a downlink error, and
• a multiple of the predetermined gradual timing adjustment, and
• the one-shot uplink timing adjustment is twice the first value.