GB2434713A

GB2434713A - Method for data reception in wireless receiver

Info

Publication number: GB2434713A
Application number: GB0601466A
Authority: GB
Inventors: Tom Vandeplas
Original assignee: Agilent Technologies Inc
Current assignee: Agilent Technologies Inc
Priority date: 2006-01-25
Filing date: 2006-01-25
Publication date: 2007-08-01
Also published as: GB0601466D0

Abstract

A method for completing or correcting data stored in a first device arranged for wireless reception of signals suitable for multimedia information transfer over a first wireless connection, said data being received incompletely or in error through the first wireless connection, said first device further being arranged for setting up a second wireless connection, said second wireless connection being bidirectional, comprising the steps of: establishing a bidirectional wireless connection between the first device and a second device, said second device being similar to the first device or being a wireless access point, checking through the bidirectional wireless connection if data missing or in error in the first device is available in the second device, transmitting the data missing or in error in the first device from the second device to the first device, completing or correcting the data in the first device using the transmitted data.

Description

METHOD FOR DATA RECEPTION IN WIRELESS RECEIVER

Field of the invention

[0001] The present invention relates to a method for receiving missing or incomplete data in e.g. a stand-alone car receiver for a car entertainment, infotainment or service system.

State of the art [0002] Car entertainment and car infotainment systems are becoming more and more complex. Customers are interested in having increased functionality and connectivity in an integrated system. In order for these systems to become a commercial success, technical solutions enabling cost reduction for the use of these multimedia devices by an average user will be needed.

[0003] Multimedia systems are becoming more and more apparent in the automotive and mobile market. Currently, DAB, T-UMTS and DVB-T are formats capable of delivering multimedia information to car-mounted systems. Another technology that can serve this market is WIMAX IEEE8O2.l6, and especially the mobile WIMAX IEEE8O2.16e variant, which will provide Internet access to mobile platforms using an extension of the WLAN technology. Similarly there is 802.20 or MBWA (Mobile Broadband Wireless Access). Although not being a broadcast or multicast technology, WIMAX could develop quickly on a commercial basis and should therefore not be ignored for this type of car based services. The quantity of systems in the field is also increasing, and therefore extra broadcasting layers are proposed such as Multimedia Broadcast Multicast Service (MEMS) . Car systems also need the reception of GPS or Galileo signals in order to allow location based services to become more effective in front of the growing user community.

[0004] The connectivity problem is mainly reflected in the cost of integrating multimedia systems in a car environment. Additional peripherals need to be installed such as an information bus, extra displays,... Today the average user is not able to spend a large amount in order to afford the system, making it suitable only for the high-end system niche.

[0005] The main disadvantages faced by current users are the cost and the quantity of separate receiver modules needed to support the different formats. Special receivers need to be purchased in order to have the necessary functionalities requested by the end user. Current consumer products support FM and DAB reception. Except for high-end cars, GPS (or future Galileo) reception requires the user to purchase an additional receiver that is mounted in the car. The current technical solutions have already reached some inter-system interaction level such as GPS/RDS (Radio Data System) . However, no solution has been found yet for future interaction between e.g. DVB-H (Digital Video Broadcast for handheld terminals), Satellite Digital Multimedia Broadcast (S-DMB), DVB-H+ (satellite extension of DVB-H) and navigation systems such as GPS or Galileo.

Most of the information received is currently audio and can be played through the car's audio system. Future systems will provide multimedia content (including images and video) and will need new user interfaces in the car, which can be expensive.

[0006] The S-DMB concept (as well as the DVB-H+ concept) is a competing system for the DVB-H terrestrial system. It is a concept originating from the mobile market.

Its purpose is to broadcast multimedia information towards mobile users on their 3G handheld terminals. The S-DMB concept is a satellite based overlay system of the 3G terrestrial networks. However, S-DMB suffers from a limited indoor penetration and a poor coverage in some environments (e.g. shadowing, large multipath profiles, ...). The S-DMB concept is currently not addressing the automotive entertainment industry. However, S-DMB service reception (as well as DVB-H+ service reception) in the car is beneficial for car passenger entertainment and infotainment', as push and store and streaming services are provided.

[0007] Typical mobile or car receivers intended for use with a variety of broadcast and navigation signals are designed to operate using a low link budget. One example of such a car receiver is disclosed in GB patent application No. 0504824.4. Due to the low link budget such systems may suffer from a significant loss of data, resulting in a need to repeat the transmission.

[0008] A car receiver system as disclosed in GB patent application No. 0504824.4 can be considered as an example of a car receiver used in the description the present invention. Such a system is a stand-alone receiver suitable for receiving a variety of broadcast schemes and navigation signals. it has a considerable local storage capability and is to be installed e.g. in the car booth or as part of the board telematics compartment. it is a small box including an antenna to be mounted on the roof of the car. This antenna can e.g. be a patch antenna providing additional gain (as compared to e.g. the antenna of a handheld wireless device), in order to boost the quality of the reception.

[0009] The receiver system can operate as an integrated system in a car multimedia environment (if available) or independently from the car's telematics system by using the mobile phone as multimedia user interface. The connection to the mobile phone is performed through a wireless interface (such as Bluetooth or WLAN) [0010] The strength of a receive-only system for reception of broadcast and navigation information is in its relative simplicity: it can be realised cost effectively and with a low power consumption/dissipation budget. No transmit section is included, which allows for a much simpler RF front-end, and the transmit power, which is the bulk of the power budget in a bidirectional communications terminal, is obviously not present.

[0011] In many cases, return channels can be realised also by combining the above communication standards with terrestrial systems, such as the already existing GSM/GPRS/UMTS, WLAN IEEE8O2.lla/b/g/ or Mobile WiMax IEEE8O2.16e, which is under development.

[0012] However, the low power budget also constitutes a drawback, as such a mobile or car receiver that can be used with a variety of broadcast and navigation signals, often relies on a link with a limited margin. The data is typically broadcast over a satellite to a receive- only terminal using a carousel system: the data is repeated several times to optimise reception. If errors or loss of link should occur the receiver will retry the reception when the data is retransmitted. Depending on the time between the retransmissions, this can take a relatively long time. In other cases, the data (video, music, ...) are streamed continuously as in a classical broadcast scenario.

Aims of the invention (0013] The present invention aims to provide a method for completing or correcting the reception of data that were received incompletely or erroneously in mobile or car receivers.

Summary of the invention

[0014] The present invention relates to a method for completing or correcting data stored in a first device arranged for wireless reception of signals suitable for multimedia information transfer over a first wireless connection, whereby the data are received incompletely or in error through said first wireless connection. The first device is further arranged for setting up a second wireless connection, said second wireless connection being bidirectional. The method comprises the steps of: -establishing a bidirectional wireless connection between the first device and a second device, said second device being similar to the first device, i.e. having similar features, -checking through the bidirectional wireless connection if data missing or in error in the first device is available in the second device, -transmitting the data missing or in error in the first device from the second device to the first device, -completing or correcting the data in the first device using the transmitted data.

[0015] In an embodiment the signals suitable for multimedia information transfer are received using a retransmission scheme, such as e.g. a carousel system. The first wireless connection is advantageously a broadcast or a multicast connection, e.g. a S-DMB, DVB-T, DVB-H or DVB-H+ connection.

[0016] In an alternative embodiment the first wireless connection is a WiMax or IEEE8O2.20 connection.

[0017] The second bidirectional wireless connection may be a Bluetooth connection or a WLAN connection according to any standard of the group comprising IEEE8O2.lla, IEEE8O2.llb, IEEE8O2.llg, IEEE8O2.lln}.

[0018] In a specific embodiment the second device is replaced by a fixed wireless access point. Optionally the fixed wireless access point comprises an integrated storage medium like a hard disk or a flash memory.

[0019] In a more specific embodiment the fixed wireless access point is arranged for prompt retransmission over the second wireless connection of data received through the first wireless connection.

[0020] Advantageously the data is transferred in packets.

[0021] In a typical practical embodiment the first device is mounted in a first car and the second device is mounted in a second car.

Short description of the drawings

[0022] Fig. 1 represents examples of different scenarios covered by the invention: (a) data restoration through communication of a car with an access point; (b) data restoration through car-to-car communication; (c) data restoration through communication of a repeater to a car.

Detailed description of the invention

[0023] A typical mobile or car receiver also has communication interfaces other than via satellite or via the terrestrial broadcast network available, including -but not limited to -wireless networking or Bluetooth, as in the above-mentioned example. Using these interfaces, the device can set up new communication links to request missing packets or packets received in error. Doing this, the device does not have to wait until the broadcast data is retransmitted. In the case of streaming data, which have been recorded (i.e. stored in the local storage medium), the communication links mentioned above can be used to replace corrupted data in the stored information.

[0024] While moving, a link can be established with other receivers moving nearby. This way, a receiver can check with other receivers whether missing packets can be made available. These other receivers moving nearby are similar to the one requesting the link. The link is established by e.g. temporarily establishing a point-to-point link (e.g. through WLAN or Bluetooth) between the requesting car and the car passing nearby. The purpose of this link is to retrieve the missing packets, and in this way to complete or correct the stored data without having to wait for the retransmission, e.g. through a carousel mechanism or any other mechanism providing redundancy.

[0025] If a wireless access point is available, the car or mobile receiver can request the missing data over the internet. Using the access point the receiver can continue the reception of data in areas which are concealed from the broadcast service. A typical use case could include the ability to download broadcast data inside buildings over a fast internet connection. This way, a user has access to all information at any time: he does no longer have to wait for the data to come in after he leaves the concealed environment.

[0026] To extend the service coverage, an access point with an integrated broadcast receiver is created.

Fixed access points can provide an improved link budget over mobile or car receivers by using specialised antennas.

Such access points could be located in parking towers, gas stations, tunnels, city centres. The access point can operate in two modes. In the first mode, the access point will continuously store the received data on an integrated storage medium such as, but not limited to, a hard disk or flash memory. A mobile or car receiver can check with the access point if data can be made available. The advantage of this mode is the ability to download a significant amount of data in a relatively short time span. In the second mode of operation, the access point will retransmit the received data over a different physical layer immediately after reception. This will allow the mobile or car receiver to select a physical layer with a higher link budget to receive the data. In this way, the access point operates as a repeater.

[0027] The advantage of access points with integrated receivers is that they can be operated in isolated areas where no other wide area networks are available. Also, the access points can provide extra or localised data.

Claims

CLAIMS

1. Method for completing or correcting data stored in a first device arranged for wireless reception of signals suitable for multimedia information transfer over a first wireless connection, said data being received incompletely or in error through said first wireless connection, said first device further being arranged for setting up a second wireless connection, said second wireless connection being bidirectional, comprising the steps of -establishing a bidirectional wireless connection between said first device and a second device, said second device being similar to said first device, -checking through said bidirectional wireless connection if data missing or in error in said first device is available in said second device, -transmitting said data missing or in error in said first device from said second device to said first device, -completing or correcting said data in said first device using said transmitted data.

2. Method for completing or correcting data as in claim 1, wherein said signals suitable for multimedia information transfer are received using a retransmission scheme.

3. Method for completing or correcting data as in claim 2, wherein said first wireless connection is a broadcast or a multicast connection.

4. Method for completing or correcting data as in claim 3, wherein said first wireless connection is a S-DMB, DVB-T, DVB-H or DVB-H+ connection.

5. Method for completing or correcting data as in claim 2, wherein said first wireless connection is a WiMax or IEEE8O2.20 connection.

6. Method for completing or correcting data as in any of claims 1 to 5, wherein said second, bidirectional wireless connection is a Bluetooth connection or a WLAN connection according to any standard of the group comprising {IEEE8O2.lla, IEEE8O2.llb, IEEE8O2.llg, IEEE8O2. un) 7. Method for completing or correcting data as in any of the previous claims, wherein said second device is replaced by a fixed wireless access point.

8. Method for completing or correcting data as in claim 7, wherein said fixed wireless access point comprises an integrated storage medium.

9. Method for completing or correcting data as in claim 8, wherein said storage medium is a hard disk or a flash memory.

10. Method for completing or correcting data as in claim 7, wherein said fixed wireless access point is arranged for prompt retransmission over said second wireless connection of data received through said first wireless connection.

11. Method for completing or correcting data as in any of the previous claims, wherein said data is transferred in packets.

12. Method for completing or correcting data as in any of the previous claims, wherein said first device is mounted in a first car and said second device is mounted in a second car.