Method, apparatus and computer program
US-2022038879-A1 · Feb 3, 2022 · US
Techniques for emergency service fall back error handling
US12520381B2 · US · B2
| Field | Value |
|---|---|
| Publication number | US-12520381-B2 |
| Application number | US-202118251780-A |
| Country | US |
| Kind code | B2 |
| Filing date | Oct 12, 2021 |
| Priority date | Nov 4, 2020 |
| Publication date | Jan 6, 2026 |
| Grant date | Jan 6, 2026 |
How to read this patent
A practical reading order for non-experts. Skip the full description unless you need deep technical detail.
- Title
What the patent document calls the invention.
- Abstract
A short plain-language summary of the technical disclosure.
- Assignees and inventors
Who owns or filed the patent and who is credited as inventor.
- Key dates
Filing, priority, publication, and grant dates set the timeline.
- First independent claim
The legal scope of protection — read this for what is actually claimed.
- CPC / IPC classifications
Technology tags used to group this patent with similar filings.
- Citations and related patents
Prior art links and similar publications in this corpus.
Abstract
Official abstract text for this publication.
A technique for establishing a voice call including receiving an indication that the first wireless system supports emergency service fallback, receiving an indication to establish an emergency voice call, transmitting an emergency service request to the first wireless system, determining that an unexpected error has occurred, selecting a second wireless system based on the determination that the unexpected error has occurred, and connecting to the second wireless system to complete the emergency voice call. Additionally, a technique for cancelling a voice call including receiving an indication that the first wireless system supports emergency service fallback, receiving an indication to establish an emergency voice call, transmitting an emergency service request to the first wireless system, receiving an indication to cancel the emergency voice call, and cancelling a connection to a second wireless system.
First claim
Opening claim text (preview).
What is claimed is: 1 . A method performed by a wireless device for establishing a voice call, the method comprising: receiving an indication that a first wireless system supports emergency service fallback; receiving an indication to establish an emergency voice call; transmitting an emergency service request to the first wireless system; determining that an unexpected error has occurred, wherein the determining comprises determining that a network congestion timer is running; selecting a second wireless system based on the determination that the unexpected error has occurred; and connecting to the second wireless system to complete the emergency voice call. 2 . The method of claim 1 , wherein the first wireless system comprises a 5G new radio (NR) wireless system, and wherein the second wireless system comprises a 4G long term evolution (LTE) wireless system. 3 . A wireless device comprising: an antenna; a radio operably coupled to the antenna; and a processor operably coupled to the radio, wherein the wireless device is configured to: receive an indication that a first wireless system supports emergency service fallback; receive an indication to establish an emergency voice call; transmit an emergency service request to the first wireless system; determine that an unexpected error has occurred, wherein determining comprises determining that a network congestion timer is running; select a second wireless system based on the determination that the unexpected error has occurred; and connect to the second wireless system to complete the emergency voice call. 4 . The wireless device of claim 3 , wherein the first wireless system comprises a 5G new radio (NR) wireless system, and wherein the second wireless system comprises a 4G long term evolution (LTE) wireless system. 5 . A non-transitory computer-readable medium that stores instructions that, when executed, cause performance of the following actions by a wireless device: receiving an indication that a first wireless system supports emergency service fallback; receiving an indication to establish an emergency voice call; transmitting an emergency service request to the first wireless system; determining that an unexpected error has occurred, wherein determining comprises determining that a network congestion timer is running; selecting a second wireless system based on the determination that the unexpected error has occurred; and connecting to the second wireless system to complete the emergency voice call. 6 . The non-transitory volatile computer-readable medium of claim 5 , wherein the first wireless system comprises a 5G new radio (NR) wireless system, and wherein the second wireless system comprises a 4G long term evolution (LTE) wireless system.
Assignees
Inventors
Classifications
Patent family
Related publications grouped by family.
External sources
Frequently asked questions
Answers are generated from the same data shown on this page.
- What does patent US12520381B2 cover?
- A technique for establishing a voice call including receiving an indication that the first wireless system supports emergency service fallback, receiving an indication to establish an emergency voice call, transmitting an emergency service request to the first wireless system, determining that an unexpected error has occurred, selecting a second wireless system based on the determination that t…
- Who is the assignee on this patent?
- Apple Inc
- What technology area does this patent fall under?
- Primary CPC classification H04W76/18. Mapped technology areas include Electricity.
- When was this patent published?
- Publication date Tue Jan 06 2026 00:00:00 GMT+0000 (Coordinated Universal Time) (B2). Legal status and post-grant events are not shown on this page.
- What related patents are in patentsdb?
- We list 6 related publications on this page (citations in our corpus or others sharing the same primary CPC).