METHOD OF ASSIGNING NETWORK ADDRESSES IN AN IN-FLIGHT ENTERTAINMENT SYSTEM

• US 20080244048A1
• Filed: 03/26/2008
• Published: 10/02/2008
• Est. Priority Date: 03/27/2007
• Status: Active Grant

• Current Assignee: Thales SA
• Original Assignee: Thales SA
• Inventors: Trinquecoste, Frederic, Durrey, Florent
• Granted Patent: US 7,921,192 B2
• Time in Patent Office: Days
• US Class Current: 709/222
• CPC Class Codes: H04L 61/5038 for local use, e.g. in LAN or USB networks, or in a controller area network [CAN]

Abstract

In an in-flight entertainment system implementing a wireless link between a network server S and wireless processing units SDB_i,j which each serve the individual devices of a plurality of seats GS_i,j of one and the same row, an identification i of the column in which a wireless processing unit SDB_i,j is positioned is carried out by providing for a sequential powering-up (PW_i-on) of the columns, the powering-up of a column coli triggering at this instant known to the server the boot process BP for the devices SDB_i,j of this column, enabling the column to be identified i by a local duration measurement b_i,j supplied by an internal clock DT_i,j of these devices previously initialized at a known instant of the boot process BP.

Claims

1. A method of assigning a network address to each of the wireless devices of a network in an aircraft, said devices being able to exchange messages with a network server via at least one access point, each device being placed in the position of a seat in a column of seats and powered by a power supply column specific to the associated column, wherein said method comprises the steps of identifying, by the server of the column of seats, of each of said wireless devices, by a sequential powering-up of the wireless devices, for each column, with a time delay of known duration between the powering-up in one column and the powering-up in a next column, said powering-up of a device triggering a mechanism for sending a message to the server, having a time indication specific to the device, the timestamp by the server of the instant at which the message was received and the identification by the server of the column of the device having sent the message, based on said time indication and said timestamp.

2. The method of assigning a network address to each of the wireless devices of a network in an aircraft, according to claim 1, in which said time delay is less than a few tenths of a second, and preferably between ten or so seconds and a few tenths of a second.

3. The method of assigning a network address to each of the wireless devices of a network in an aircraft, according to claim 1, in which said sequential powering-up triggers in a device:

a). a boot process comprising an initialization of an internal clock,

b). after said initialization, sending to the network server of at least one acknowledgement packet by said device, said acknowledgement packet comprising a current value of the internal clock of said device at the moment of said sending and characterized in that the identification by the network server of the column of a device on reception of an acknowledgement packet from this device is performed on the basis of said current value contained in said packet and the time of reception of said acknowledgement packet supplied by the internal clock of the network server.

4. The method according to claim 3, in which each wireless device uses a packet sending mode of the type with packet receipt confirmation, and sends at determined intervals a new packet containing the corresponding current value of said timestamping device, until a corresponding confirmation of receipt is received.

5. The method according to claim 3, in which the server sends a column identification i to a device sending an acknowledgement packet in an acknowledgement of said acknowledgement packet.

6. The method according to claim 3, such that, when an identification process is triggered, the network server executes the following steps:

a) activation of a loop for sequentially powering up wireless devices in columns of seats;

b) for i=0 up to n, n being an integer number corresponding to the number of columns;

i) i=i+1

ii) powering up of the column i;

iii) time delay, for a time delay duration then return to b)

c) for each received packet, storage of the current value transmitted in said packet and of the local time of reception of this packet by the server;

d) for each pair (local reference value, local reception time), determination of an associated column number i.

7. The method according to claim 6, in which said column identification is given by the rank i of this column in the sequential powering-up loop and it is performed by means of calculating the following equation:

i=(t_i,j−

t₁−

b_i,j−

s₀)/(Δ

+1), where so is the average duration of the duration of the boot process of a device between the instant at which this boot process is activated and the initialization of the internal clock of the device, and t₁ is the instant when the first column is powered up by the sequential powering-up loop.

8. The method according to claim 7, in which the values s₀ and Δ

vary according to the system operating time.

9. In-flight entertainment system comprising a network server and wireless devices able to exchange messages with the network server via at least one access point, each device being placed in the position of a seat in a column of seats and powered by a power supply column specific to the associated column, the server supplies each wireless device with an identification of the column in which it is placed, by applying an address assignment process according claim 1.