System and method for communicating using an in-vehicle system
A system and method for communicating wirelessly from a mobile device to a remote receiver station is disclosed. The system includes a controller configured to monitor a status of the mobile device and, upon an initiation event, initiate a data transfer process to wirelessly communicate data to the remote receiver station. The system also includes a voice-band modem that, upon initiation of the data transfer process. The voice-band modem is configured to receive data for transfer to the remote receiver station, encode the data using a fountain code encoding protocol to form a series encoded packets, and repeatedly transmit the encoded packets until receiving an indication that the series of packets has been received at the receiving station.
1. A mobile device for communicating wirelessly with a remote receiver station, the mobile device comprising:
a controller configured to monitor a status of the mobile device and, upon an initiation event, initiate a data transfer process to wirelessly communicate data to the remote receiver station; and
a voice-band modem that, upon initiation of the data transfer process, is configured to:
receive data for transfer to the remote receiver station,
encode the data using a fountain code encoding protocol to form a series of encoded packets, and
transmit, in the voice-band, the encoded packets until receiving an indication that the series of packets has been received at the receiving station, and
wherein the voice-band modem is further configured to arrange a set of source data and a checksum into a set of source packets sufficient to send the data for transfer to the remote receiver station, wherein the voice-band modem is further configured to assign a sequential number and a randomly generated vector to the source packets to encode the data, and wherein the voice-band modem is further configured to encode source packets according to the following equation:
e
n
=
(
∑
k
=
0
K
-
1
G
n
(
k
)
·
p
k
)
mod
2
;
where e n represents an encoded packet, G n represents a vector for the encoded packet e n , and p k represents a source packet.
2. The mobile device of claim 1 wherein:
the fountain code encoding protocol includes using a random linear fountain code; or
the mobile device is an in-vehicle communication system and the remote receiver station is a public safety answering point.
3. The mobile device of claim 1 wherein the voice-band modem is configured to encode the encoded packets as a modulo 2 bitwise sum of the source packets.
4. The mobile device of claim 1 wherein the voice-band modem is further configured to assign a sequential number and a deterministically generated vector to the source packets to encode the data.
5. The mobile device of claim 1 wherein a trigger signal received from the receiving station is used to indicate a readiness of the receiving station to receive the series of encoded packets and wherein the indication that the series of packets has been received at the receiving station is the discontinuation of the trigger signal.
6. A method in a remote receiver station including an answering point device for communicating wirelessly with a mobile device, the method comprising:
opening a communications connection with the mobile device;
receiving, in a voice-band, a series of encoded packets, encoded using a fountain code encoding protocol, from the mobile device over the communications connection; and
decoding the encoded packets;
identifying a packet number associated with each encoded packet;
associating each encoded packet with a corresponding vector using the packet number;
arranging each encoded packet and corresponding vector in a matrix; and
inverting the matrix to decode the encoded packets
communicating a trigger signal over the communications connection to indicate a readiness to receive the series of encoded packets from the mobile device over the communications connection; and
including a pre-determined binary pseudorandom sequence in the trigger signal.
7. The method of claim 6 further comprising continuing to communicate a trigger signal over the communications connection to indicate a continued readiness to receive the series of encoded packets from the mobile device over the communications connection and discontinuing the trigger signal to indicate that the series of encoded packets was received from the mobile device over the communications connection.
8. The method of claim 6 wherein the encoded packets include a deterministically generated vector.
9. A method in a remote receiver station including an answering point device for communicating wirelessly with a mobile device, the method comprising:
opening a communications connection with the mobile device;
receiving, in a voice-band, a series of encoded packets, encoded using a fountain code encoding protocol, from the mobile device over the communications connection; and
decoding the encoded packets;
identifying a packet number associated with each encoded packet;
associating each encoded packet with a corresponding vector using the packet number;
arranging each encoded packet and corresponding vector in a matrix; and
inverting the matrix to decode the encoded packets
communicating a trigger signal over the communications connection to indicate a readiness to receive the series of encoded packets from the mobile device over the communications connection, wherein the encoded packets are encoded according to the following equation:
e
n
=
(
∑
k
=
0
K
-
1
G
n
(
k
)
·
p
k
)
mod
2
;
where e n represents an encoded packet, G n represents a vector for the encoded packet e n , and p k represents a source packet, optionally wherein the source packet includes a set of source data and a checksum.