Apparatus, Systems and Methods for Switching Between Radio Access Technologies

Patent metadata

Field	Value
Publication number	US-2016353344-A1
Application number	US-201514727550-A
Country	US
Kind code	A1
Filing date	Jun 1, 2015
Priority date	May 29, 2015
Publication date	Dec 1, 2016
Grant date	—

Abstract

A user equipment (“UE”) connected to a first network that performs methods including receiving a page from the first network indicating an incoming voice call, when it is determined the voice call was not successfully connected, incrementing a value of a counter and when the value satisfies the threshold, switching from the first network to a second network. Another method includes originating a voice call via the first network, when it is determined the voice call was not successfully connected, opening a socket connection with the first network and attempting to re-originate the voice call via the first network. Another method includes determining whether the UE has switched a connection from a first network to a second network and when it is determined that the UE has switched the connection to the second network, initiating an action by the

First claim

What is claimed is:

1 . A method, comprising:
at a user equipment (“UE”) connected to a first network:
receiving a page from the first network indicating an incoming voice call;
determining whether the voice call was successfully connected;
when it is determined the voice call was not successfully connected, incrementing a value of a counter;
determining whether the value of the counter satisfies a threshold; and
when the value satisfies the threshold, switching from the first network to a second network.

2 . The method of claim 1 , wherein the first network is a Long Term Evolution (LTE) network and the incoming voice call is a Voice over LTE (VoLTE) call and the second network is a network that handles voice calls using a circuit switched network.

3 . The method of claim 2 , wherein the second network is one of a Global System for Mobile (GSM) network, a Universal Mobile Telecommunications System (UMTS) network, a Code Division Multiple Access (CDMA) network or a CDMA 2000 1x network.

4 . The method of claim 1 , further comprising:
when the voice call is successfully connected, resetting the value of the counter to an original value.

5 . The method of claim 1 , further comprising:
when it is determined the voice call was not successfully connected and the value of the counter does not satisfy the threshold, performing one of:
re-attempting to respond to the page of the first network to connect the voice call; or
waiting to receive a second page for the voice call from the first network.

6 . The method of claim 1 , wherein the value of the counter that satisfies the threshold is based on measured properties of a reference signal received by UE.

7 . The method of claim 6 , wherein the measured properties of the reference signal include one of a Received Signal Strength Indicator (“RSSI”), a Reference Signal Received Power (“RSRP”), or a Reference Signal Received Quality (“RSRQ”).

8 . A method, comprising:
at a user equipment (“UE”) connected to a first network:
originating a voice call via the first network;
determining whether the voice call was successfully connected;
when it is determined the voice call was not successfully connected, opening a socket connection with the first network; and
attempting to re-originate the voice call via the first network.

9 . The method of claim 8 , further comprising:
when it is determined the voice call was not successfully connected, starting a timer; determining whether the timer has expired; and when the timer has not expired, continuing to attempt to re-originate the voice call via the first network.

10 . The method of claim 9 , further comprising:
when the timer expires and the voice call is not successfully connected, switching from the first network to a second network.

11 . The method of claim 8 , wherein the determining whether the voice call was successfully connected, includes:
determining whether there is an open socket connection for the voice call.

12 . The method of claim 8 , wherein the first network is a Long Term Evolution (LTE) network and the voice call is a Voice over LTE (VoLTE) call.

13 . The method of claim 8 , wherein the socket connection is a TCP connection with a Proxy-Call Session Control Function (P-CSCF) of an IP Multimedia Subsystem (IMS).

14 . A method, comprising:
at a user equipment (“UE”):
determining whether the UE has switched a connection from a first network to a second network; and
when it is determined that the UE has switched the connection to the second network, initiating an action by the UE, wherein the action includes one of:
re-initiating a TCP connection with a Proxy-Call Session Control Function (P-CSCF) of an IP Multimedia Subsystem (IMS) of the second network;
resetting a registration timer of the UE, wherein the registration timer is based on a connection with the IMS of the second network and wherein when the registration timer expires, the UE reinitiates a TCP connection with the P-CSCF of the IMS of the second network; and
sending feedback from a lower layer of a network stack of the UE to a higher layer of the network stack of the UE, wherein the feedback is based on a connection with the IMS of the second network.

15 . The method of claim 14 , wherein the UE had a previous connection to the second network before connecting to the first network.

16 . The method of claim 14 , wherein the resetting of the registration timer causes the registration timer to expire.

17 . The method of claim 14 , wherein the resetting of the registration timer causes the registration timer to have a shorter duration than an original duration.

18 . The method of claim 14 , wherein, prior to the resetting of the registration timer, the method further comprises:
determining an amount of traffic between a lower layer of a network stack of the UE and the IMS.

19 . The method of claim 14 , further comprising:
based on the feedback from the lower layer of the network stack, re-initiating a TCP connection with the P-CSCF of the IMS of the second network.

20 . The method of claim 14 , wherein the second network is a Long Term Evolution (LTE) network.

Assignees

• Apple Inc

Inventors

• Deivasigamani Giri Prassad
• Cili Gencer
• Volkert Christopher A
• Alam Muhammad A
• Nukala Guarav
• Verger Luciano M
• Karandikar Yogesh D
• Vasudeven Srinivasan
• Lakshman Deepak Chitlur

Classifications

• H04W36/30

  by measured or perceived connection quality data · CPC title

• H04W48/18

  Selecting a network or a communication service · CPC title

• H04W88/06

  adapted for operation in multiple networks {or having at least two operational modes}, e.g. multi-mode terminals · CPC title

• H04W24/10 Primary

  Scheduling measurement reports {; Arrangements for measurement reports} · CPC title

• H04M15/57

  for integrated multimedia messaging subsystem [IMS] · CPC title