Time Synchronization Method and System, and Network Device
First Claim
1. A time synchronization method, comprising:
- receiving, by a second network device, a first packet from a first network device, wherein the first packet comprises a first service frame and a first time stamp (T1), wherein the first network device is coupled to a radio equipment control (REC), wherein the second network device is coupled to a radio equipment (RE), wherein the first network device keeps system time synchronization with the second network device, wherein the first service frame is from the REC to the first network device and carries a system clock of the REC, and wherein the T1 is a time stamp at which the first network device receives the first service frame;
obtaining, by the second network device, the system clock of the REC according to the first packet;
sending, by the second network device according to the system clock of the REC, the first service frame extracted from the first packet to the RE;
recording, by the second network device according to a system time of the second network device, a second time stamp (T2) at which the first service frame is sent by the second network device; and
calculating, by the second network device, a transmission delay (T) between the first network device and the second network device, wherein the T=T2−
T1.
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Accused Products
Abstract
A time synchronization method and system, and a network device, where the method includes receiving, by a second network device, a first packet from a first network device, where the first packet includes a first service frame and a first time stamp (T1), the first service frame carries a system clock of a radio equipment control (REC), obtaining, the system clock of the REC according to the first packet, sending, according to the system clock of the REC, the first service frame extracted from the first packet to a radio equipment (RE), recording a second time stamp (T2) at which the first service frame is sent, and determining, by the second network device, a transmission delay (T) according to T=T2−T1. Hence, a delay between the REC and the RE remains unchanged.
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Citations
10 Claims
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1. A time synchronization method, comprising:
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receiving, by a second network device, a first packet from a first network device, wherein the first packet comprises a first service frame and a first time stamp (T1), wherein the first network device is coupled to a radio equipment control (REC), wherein the second network device is coupled to a radio equipment (RE), wherein the first network device keeps system time synchronization with the second network device, wherein the first service frame is from the REC to the first network device and carries a system clock of the REC, and wherein the T1 is a time stamp at which the first network device receives the first service frame; obtaining, by the second network device, the system clock of the REC according to the first packet; sending, by the second network device according to the system clock of the REC, the first service frame extracted from the first packet to the RE; recording, by the second network device according to a system time of the second network device, a second time stamp (T2) at which the first service frame is sent by the second network device; and calculating, by the second network device, a transmission delay (T) between the first network device and the second network device, wherein the T=T2−
T1. - View Dependent Claims (2, 3, 4)
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5. A first network device that is coupled to a radio equipment control (REC) and that keeps system time synchronization with a second network device, wherein the second network device is coupled to a radio equipment (RE), and wherein the first network device comprises:
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a processor; and a memory coupled to the processor and configured to store program instructions and data, wherein the program instructions and data cause the processor to be configured to; receive a service frame from the REC; record, according to a system time of the first network device, a first time stamp (T1) at which the service frame is received, wherein the service frame carries a system clock of the REC; and send a packet to the second network device, wherein the packet comprises the service frame and the T1, and wherein the packet notifies the system clock of the REC and the T1 to the second network device. - View Dependent Claims (6)
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7. A second network device that is coupled to a radio equipment (RE) and that keeps system time synchronization with a first network device, wherein the first network device is coupled to a radio equipment control (REC), and wherein the second network device comprises:
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a memory configured to store program instructions and data; and a processor coupled to the memory, wherein the program instructions and the data stored in the memory cause the processor to be configured to; receive a first packet from the first network device, wherein the first packet comprises a first service frame and a first time stamp (T1), wherein the first service frame is from the REC to the first network device and carries a system clock of the REC, and wherein the T1 is a time stamp at which the first network device receives the first service frame; obtain the system clock of the REC according to the first packet; send, according to the system clock of the REC, the first service frame extracted from the first packet to the RE; record, according to a system time of the second network device, a second time stamp (T2) at which the first service frame is sent by the processor; and calculate a transmission delay (T) between the first network device and the second network device, wherein the T=T2−
T1. - View Dependent Claims (8, 9, 10)
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Specification