Wireless multicast transmission and recovery

Patent metadata

Field	Value
Publication number	US-10135947-B1
Application number	US-201615212941-A
Country	US
Kind code	B1
Filing date	Jul 18, 2016
Priority date	Jul 18, 2016
Publication date	Nov 20, 2018
Grant date	Nov 20, 2018

Abstract

A transmission system that sends data to multiple devices simultaneously using multiple access points (APs). The system may send multicast data (e.g., original transmission of multicast data) to the multiple devices using a first AP and may send recovery data (e.g., retransmission of portions of the multicast data) to individual devices using a second AP. As the second AP handles requests for the recovery data and sends the recovery data, the first AP may send the multicast data using all available bandwidth and an efficiency of transmission does not depend on the number of devices connected to the first AP. The recovery data may be determined based on an original manifest of the multicast data, such as a bitmap or other representation, and the device may generate a recovery manifest indicating the recovery data and send the recovery manifest to the second AP.

First claim

What is claimed is:

1. A computer-implemented method for downloading and recovering multicast data by a mobile device, the method comprising:
establishing a first wireless communication link between the mobile device and a control access point, the control access point communicatively coupled to a server;
sending a registration request to the server via the control access point, the registration request indicating an identity of the mobile device;
receiving a first bitmap corresponding to multicast data to be broadcasted by a multicast access point, the first bitmap including first entries corresponding to a first portion of the multicast data and second entries corresponding to a second portion of the multicast data;
receiving a network address of the multicast access point, the multicast access point communicatively coupled to the server and storing the multicast data;
terminating the first wireless communication link;
after the first wireless communication link has been terminated, establishing, using the network address, a second wireless communication link between the mobile device and the multicast access point;
receiving, from the multicast access point, the first portion of the multicast data;
determining that the first portion of the multicast data does not include multicast data corresponding to the second entries in the first bitmap;
determining, based at least in part on determining that the first portion of the multicast data does not include data corresponding to the second entries, that the second portion of the multicast data was not received by the mobile device;
creating a second bitmap corresponding to the multicast data and indicative of the second portion of the multicast data;
terminating the second wireless communication link;
after the second wireless communication link has been terminated, establishing a third wireless communication link between the mobile device and the control access point;
sending the second bitmap to the control access point; and
receiving, from the control access point, the second portion of the multicast data.

2. The computer-implemented method of claim 1 , further comprising: receiving, from the multicast access point, a first data packet included in the first portion of the multicast data; determining a sequence number associated with the first data packet; determining a memory address corresponding to the first data packet; modifying a value in the second bitmap corresponding to the sequence number to indicate reception of the first data packet; and storing data included in the first data packet in the memory address.

3. The computer-implemented method of claim 1 , further comprising: generating combined data by combining the first portion of the multicast data and the second portion of the multicast data; displaying, on a display and using the combined data, first content; requesting, from the control access point, second content; receiving a third bitmap corresponding to second multicast data to be sent by a second multicast access point; receiving a second network address of the second multicast access point, the second multicast access point communicatively coupled to the server and storing the second multicast data, the second multicast data corresponding to the second content; receiving, from the second multicast access point, a first portion of the second multicast data; receiving, from the control access point, a second portion of the second multicast data; generating second combined data by combining the first portion of the second multicast data and the second portion of the second multicast data; and displaying, on the display and using the second combined data, the second content.

4. The computer-implemented method of claim 1 , further comprising, by the server: receiving, from the mobile device via the control access point, the second bitmap; determining that a first bit of the second bitmap indicates that first data was not received by the mobile device; determining the first data; determining that a second bit of the second bitmap indicates that second data was not received by the mobile device; determining the second data: generating, from the second bitmap, recovery data corresponding to the second portion of the multicast data, the recovery data including the first data and the second data; and sending the recovery data to the mobile device via the control access point.

5. A computer-implemented method, comprising, by a device:
establishing a first wireless communication link between the device and a first access point;
receiving, from the first access point, a first bitmap corresponding to first data to be sent by a second access point, the second access point storing the first data, the first bitmap including first entries corresponding to a first portion of the first data and second entries corresponding to a second portion of the first data;
receiving, from the first access point via the first wireless communication link, a network address of the second access point;
after the first wireless communication link has been terminated, establishing, using the network address, a second wireless communication link between the device and the second access point;
receiving, from the second access point via the second wireless communication link, the first portion of the first data;
determining that the first portion of the first data does not include data corresponding to the second entries in the first bitmap;
determining, based at least in part on determining that the first portion of the first data does not include data corresponding to the second entries, that the second portion of the first data was not received by the device; creating a second bitmap corresponding to the first data and indicative of the second portion of the first data;
after the second wireless communication link has been terminated, establishing a third wireless communication link between the device and the first access point;
sending the second bitmap to the first access point via the third wireless communication link; and
receiving, from the first access point, the second portion of the first data.

6. The computer-implemented method of claim 5 , further comprising: receiving, from the second access point at a first time, the first portion of the first data; determining that a third portion of the first data was not received by the device; receiving, from a third access point at a second time after the first time, the first portion of the first data; receiving, from the third access point at a third time after the first time, the third portion of the first data.

7. The computer-implemented method of claim 5 , further comprising: receiving a third bitmap corresponding to second data to be sent by a third access point, the third access point storing the second data, and the third bitmap including third entries corresponding to a first portion of the second data and fourth entries corresponding to a second portion of the second data; receiving, from the third access point, the first portion of the second data; determining that the first portion of the second data does not include data corresponding to the fourth entries in the third bitmap; determining, based at least in part on determining that the first portion of the second data does not include data corresponding to the fourth entries, that the second portion of the second data was not received by the device; creating a fourth bitmap corresponding to the second data and indicative of the second portion of the second data; sending the fourth bitmap to the first access point; receiving, from the first access point, the second portion of the second data; and generating combined data by combining the first portion of the first data, the second portion of the first data, the fir

Assignees

• Amazon Tech Inc

Inventors

• Chen Yajun
• Zhan Peng
• Ma Qingyuan
• Zhou Zhen

Classifications

• H04W76/10

  Connection setup · CPC title

• G06F8/61

  Installation · CPC title

• H04L12/1868

  Measures taken after transmission, e.g. acknowledgments · CPC title

• G06F8/65

  Updates (security arrangements therefor G06F21/57) · CPC title

• H04W4/06 Primary

  Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services · CPC title