Method for coordinating measurements and calibrations in a passive optical network

• US 20090220226A1
• Filed: 01/29/2009
• Published: 09/03/2009
• Est. Priority Date: 02/04/2008
• Status: Active Grant

• Current Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Original Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Inventors: Heidemann, Richard, Hehmann, Jorg
• Granted Patent: US 8,180,217 B2
• Time in Patent Office: Days
• US Class Current: 398/25
• CPC Class Codes: H04J 3/0682 by delay compensation, e.g. by compensation of propagation delay or variations thereof, by ranging
• CPC Class Codes: H04J 3/14 Monitoring arrangements for SDH/SONET rings H04J3/085
• CPC Class Codes: H04J 3/1694 Allocation of channels in TDM/TDMA networks, e.g. distributed multiplexers Passive Optical Networks H04Q11/0062
• CPC Class Codes: H04Q 11/0067 Provisions for optical access or distribution networks, e.g. Gigabit Ethernet Passive Optical Network (GE-PON), ATM-based Passive Optical Network (A-PON), PON-Ring
• CPC Class Codes: H04Q 2011/0079 Operation or maintenance aspects
• CPC Class Codes: H04Q 2011/0083 Testing; Monitoring

Abstract

Method for coordinating measurements and calibrations in a passive optical network, PON, in particular in a Gigabit PON, the method comprising: generating, in an optical line termination (3), OLT, a downstream frame (25), transmitting the downstream frame (25) from the OLT to a plurality of optical network terminations (6.1 to 6.n), ONTs, the downstream frame (25) comprising at least one allocation structure (10) for allocating to at least one targeted ONT (6.1 to 6.n) a time slot for transmitting upstream data, the allocation structure (10) indicating that the type of upstream data to be transmitted during the allocated time slot is measurement data (26) or calibration data.

Claims

1. Method for coordinating measurements and calibrations in a passive optical network, PON, in particular in a Gigabit PON, the method comprising:

generating, in an optical line termination OLT, a downstream frame, transmitting the downstream frame from the OLT to a plurality of optical network terminations, ONTs, the downstream frame comprising at least one allocation structure for allocating to at least one targeted ONT a time slot for transmitting upstream data, the allocation structure indicating that the type of upstream data to be transmitted during the allocated time slot is measurement data or calibration data.

2. Method according to claim 1, wherein no upstream data is received by the OLT during a measurement time interval between the start of the transmission of the downstream frame and the reception of the measurement or calibration data from the targeted ONT having maximum distance from the OLT.

3. Method according to claim 2, wherein during the measuring time interval, the OLT only generates downstream frames which allocate time slots for upstream data which is transmitted after the measuring time interval.

4. Method according to claim 1, wherein the time slots allocated to the targeted ONTs are chosen in such a way that the measurement data or calibration data of different targeted ONTs is received concurrently at the OLT.

10. Computer program product comprising code for implementing the method according to claim 1.

5. Optical network termination, ONT, comprising:

a data generation unit for generating measurement data or calibration data in a time slot allocated by an allocation structure of a downstream frame indicating that the type of upstream data to be transmitted during the allocated time slot is measurement data or calibration data.

6. Passive optical network, PON, in particular Gigabit PON, comprising:

a plurality of ONTs according to claim 5 arranged in branches of the PON which are connected to a main line, and

an optical line termination, OLT, arranged at a head end of the main line, the OLT comprising;

a frame generator for generating a downstream frame to be transmitted from the OLT to the ONTs, the downstream frame comprising at least one allocation structure for allocating to at least one targeted ONT a time slot for sending upstream data, the allocation structure generated by the frame generator being adapted to indicate that the type of upstream data to be transmitted in the allocated time slot is measurement data or calibration data.

7. Passive optical network according to claim 6, wherein the frame generator of the OLT is adapted to generate only downstream frames which do not allocate time slots for transmitting upstream data received by the OLT during a measurement time interval between the start of the transmission of the downstream frame and the reception of the measurement data or calibration data from the targeted ONT having maximum distance from the OLT.

8. Passive optical network according to claim 7, wherein the OLT further comprises a frame transmission time determination unit for determining the transmission time of the downstream frame from the OLT to the ONTs.

9. Passive optical network according to claim 6, wherein the frame generator of the OLT is adapted to generate a downstream frame, in particular based on the structure of the Gigabit passive optical network protocol, having at least one allocation structure which comprises a flags field with a flag bit indicating that the type of upstream data to be transmitted during the allocated time slot is measurement data and a further flag bit indicating that the type of upstream data to be transmitted during the allocated time slot is calibration data.