# US 2019/0246433 A1 · Random Access for a Wireless Device

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2019/0246433 A1
- Document ID: US20190246433A1
- Status: Published application
- Kind: A1
- Application number: 16/315,272
- Filed: 2016-07-06
- Published: 2019-08-08
- Earliest claimed: 2016-07-06
- Assignees: Telefonaktiebolaget LM Ericsson (publ)
- Applicants: Telefonaktiebolaget LM Ericsson (publ)
- Inventors: Guowei Zhu
- Web page: https://patentgrep.com/patent/US20190246433A1

## CPC

- H04W 74/0833: Random access procedures, e.g. with 4-step access
- H04L 5/0037: {Inter-user or inter-terminal allocation}
- H04L 5/0053: {Allocation of signalling, i.e. of overhead other than pilot signals}
- H04L 5/0064: {Rate requirement of the data, e.g. scalable bandwidth, data priority}
- H04L 5/0073: {Allocation arrangements that take into account other cell interferences}
- H04W 52/0225: {using monitoring of external events, e.g. the presence of a signal}
- Y02D 30/70: in wireless communication networks
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)
- Y02D: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE

## Abstract

There is provided mechanisms for random access. A method is performed by a wireless device. The method comprises transmitting a random access preamble to a network node. The method comprises determining a valid starting subframe of a random access response window for monitoring a common search space for a random access response from the network node. Starting time of the random access response window is adapted such that it starts with the valid subframe. The method comprises monitoring the common search space for the random access response only during the random access response window.

## Claims

### Claim 1

A method for random access, the method being performed by a wireless device, the method comprising:
transmitting a random access preamble to a network node;
determining a valid starting subframe of a random access response window for monitoring a common search space for a random access response from the network node, wherein starting time of the random access response window is adapted such that it starts with the valid subframe; and
monitoring the common search space for the random access response only during the random access response window.

### Claim 2 (depends on 1)

The method according to claim 1, wherein the valid starting subframe is denoted a candidate starting subframe, wherein the random access preamble is transmitted at time t1, the method further comprising:
determining, when the candidate starting subframe is distanced at most two subframes from said time t1, a next valid starting subframe of the random access response window.

### Claim 3 (depends on 1)

The method according to claim 1, further comprising:
operating in a power saving mode between transmitting the random access preamble and monitoring the common search space.

### Claim 4 (depends on 3)

The method according to claim 3, wherein the random access preamble is transmitted at time t1, the method further comprising:
switching to said power saving mode.

### Claim 5 (depends on 4)

The method according to claim 4, further comprising:
receiving a random access response from the network node in the random access response window;
transmitting a radio resource control connection request message to the network node in response thereto.

### Claim 6 (depends on 5)

The method according to claim 5, further comprising:
activating a Medium Access Control, MAC, contention resolution timer when having transmitted the radio resource control connection request message, wherein the MAC contention resolution timer starts at a valid starting subframe of a common search space for a response from the network node to the radio resource control connection request message.

### Claim 7 (depends on 6)

The method according to claim 6, wherein the MAC contention resolution timer is a MAC-ContentionResolutionTimer-r13.

### Claim 8 (depends on 6)

The method according to claim 6, wherein the radio resource control connection request message is transmitted at time t2, the method further comprising:
determining, when the valid starting subframe for the response from the network node to the radio resource control connection request message occurs earlier than said time t2, a next valid starting subframe of the random access response window for the response from the network node to the radio resource control connection request message.

### Claim 9 (depends on 6)

The method according to claim 6, further comprising:
operating in a power saving mode between transmitting the radio resource control connection request message and activating the MAC contention resolution timer.

### Claim 10 (depends on 9)

The method according to claim 9, wherein the radio resource control connection request message is transmitted at time t2, the method further comprising:
switching to said power saving mode; and
switching back to normal mode from said power saving mode at the valid starting subframe for the response from the network node to the radio resource control connection request message, wherein the MAC contention resolution timer is activated in response thereto.

### Claim 11 (depends on 1)

The method according to claim 1, wherein the common search space is a Machine-Type Communications Physical Downlink Control Channel, MPDCCH.

### Claim 12 (depends on 11)

The method according to claim 11, wherein the common search space is a MPDCCH Type2 common search space.

### Claim 13 (depends on 1)

The method according to claim 1, wherein the valid starting subframe is determined based on an absolute subframe number, nsfabs, within a system frame number wrap-around period.

### Claim 14 (depends on 1)

The method according to claim 1, wherein the valid starting subframe is determined according to
(10nf+└ns/2┘)mod TMPDCCH=0,
where nf denotes system frame number, where ns denotes slot number within radio frame, where TMPDCCH=Rmax·G, where Rmax is a maximum repetition level, and where G is an integer.

### Claim 15 (depends on 14)

The method according to claim 14, wherein Rmax is one value of {1, 2, 4, 8, 16, 32, 64, 128, 256} with index given by a parameter mpdch-NumRepetition-RA-r13.

### Claim 16 (depends on 14)

The method according to claim 14, wherein G is one value of {1, 1.5, 2, 2.5, 4, 5, 8, 10} or one value of {, 2, 4, 5, 8, 10, 20, spare1} with index given by a parameter mpdcch-startSF-CSS-RA-r13.

### Claim 17

(canceled)

### Claim 18

A wireless device for random access, the wireless device comprising:
processing circuitry; and
a computer program product storing instructions that, when executed by the processing circuitry, causes the wireless device to:
transmit a random access preamble to a network node;
determine a valid starting subframe of a random access response window for monitoring a common search space for a random access response from the network node, wherein starting time of the random access response window is adapted such that it starts with the valid subframe; and
monitor the common search space for the random access response only during the random access response window.

### Claim 19

(canceled)

### Claim 20

A computer program for random access, the computer program comprising computer code which, when run on processing circuitry of a wireless device, causes the wireless device to:
transmit a random access preamble to a network node;
determine a valid starting subframe of a random access response window for monitoring a common search space for a random access response from the network node, wherein starting time of the random access response window is adapted such that it starts with the valid subframe; and
monitor the common search space for the random access response only during the random access response window.

### Claim 21 (depends on 20)

A computer program product comprising a computer program according to claim 20, and a computer readable storage medium on which the computer program is stored.