CN107395308A - A kind of Distributed Wireless Sensor Networks method for synchronizing time of low memory cost - Google Patents
A kind of Distributed Wireless Sensor Networks method for synchronizing time of low memory cost Download PDFInfo
- Publication number
- CN107395308A CN107395308A CN201710574605.5A CN201710574605A CN107395308A CN 107395308 A CN107395308 A CN 107395308A CN 201710574605 A CN201710574605 A CN 201710574605A CN 107395308 A CN107395308 A CN 107395308A
- Authority
- CN
- China
- Prior art keywords
- node
- msub
- mrow
- timestamp
- beacon
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W56/00—Synchronisation arrangements
- H04W56/001—Synchronization between nodes
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J3/00—Time-division multiplex systems
- H04J3/02—Details
- H04J3/06—Synchronising arrangements
- H04J3/0635—Clock or time synchronisation in a network
- H04J3/0638—Clock or time synchronisation among nodes; Internode synchronisation
- H04J3/0658—Clock or time synchronisation among packet nodes
- H04J3/0661—Clock or time synchronisation among packet nodes using timestamps
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W4/00—Services specially adapted for wireless communication networks; Facilities therefor
- H04W4/70—Services for machine-to-machine communication [M2M] or machine type communication [MTC]
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Mobile Radio Communication Systems (AREA)
- Synchronisation In Digital Transmission Systems (AREA)
Abstract
The invention discloses a kind of Distributed Wireless Sensor Networks synchronous method of low memory cost, this method is to be based on distributed average algorithm, and each node memory size is controllable, and each nodal function is consistent in network, no reference mode and fixed topology；Each node periodically sends sync beacon, enters row clock adjustment using the data in the sync beacon received；Node sends the historical time stamp data being locally stored when sending sync beacon simultaneously, and receiving node can directly find available timestamp in sync beacon, data are locally stored without searching；Sending node discharges the data having been used by memory management scheme in time, reaches the purpose for reducing EMS memory occupation.The present invention can allow small, the cheap radio node of internal memory to apply in large-scale dynamic network and intensive distributed network.
Description
Technical field
The present invention relates to a kind of radio sensing network method for synchronizing time, more particularly to a kind of distribution of low memory cost
Radio sensing network synchronous method.
Background technology
Radio sensing network is made up of a large amount of sensor nodes, possesses data acquisition, communication and disposal ability.With technology
Continuous maturation, radio sensing network is used in more and more with the features such as its cost is low, networking is convenient, low-power consumption
The fields such as Internet of Things household, Industry Control and health care.
Time synchronized is one of hot issue of radio sensing network research, in target tracking, network management, electric monitoring
Deng in network application, high-precision time synchronized is the basis of data processing and ensured.Because sensing network interior joint clock is brilliant
The technique shaken has differences, and the factor such as temperature and voltage influences, and causes crystal oscillator to count inaccurate, it is each to result in different nodes
Inconsistent phenomenon from clock be present, their clock can be deviated from each other gradually.
Traditional method for synchronizing time includes RBS (Reference-Broadcast Synchronization), TPSN
(Timing-sync Protocol for Sensor Networks), FTSP (Flooding Time Synchronization
Protocol) etc., this kind of Time synchronization algorithm is typically required for reference mode to provide the reference time for other nodes, thus claims
Be centralized synchronized algorithm.Centralized synchronized algorithm can generally have synchronizing speed and less network overhead quickly.But
Because they depend on reference mode and specific topological network (such as TPSN, FTSP need tree network), the loss of node
Addition with new node all easily causes the failure of synchronized algorithm, thus centralized Time synchronization algorithm poor robustness, it is difficult to should
For dynamic network.
Distributed Time synchronized algorithm is independent of reference mode and network topology.It is distribution wherein than more prominent algorithm
Formula average algorithm, such as classical Distributed Time synchronized algorithm ATS (L.Schenato and F.Fiorentin, " Average
TimeSynch:A consensusbased protocol for clock synchroniza-tion in wireless
sensor networks,”Automatica,vol.47,no.9,pp.1878-1886,2011.).In distributed average algorithm,
Each node exchanges shared information with its neighbor node, and calculates statistical average using the information obtained, to adjust oneself
Clock, so as to reach the time synchronized of whole network.This distributed structure/architecture can provide very high robustness and scalability,
Improve network stabilization.
Compared to centralized time synchronized, Distributed Time can synchronously be more suitable for large-scale, dynamic wireless sensing
In network.Need to store the information of a large amount of neighbor nodes yet with each node in distributed synchronization algorithm, network be present and open
Pin is big, node memory takes the problem of high, limits its application.
Nodal clock model：In radio sensing network, clock readings of any one node i in time of day t can be with
Represented with formula (1)：
τi(t)=ait+bi (1)
Wherein aiFor nodal clock crystal oscillator drift rate, biFor clock skew.In order to adjust clock, ATS algorithms propose new tune
Whole clock models：
WhereinFor drift rate adjustment parameter,For offset adjusted parameter, therefore ATS synchronized algorithms aim at adjustment
Each nodeSo that clock C after the adjustment of node all in networki(t) reach consistent.
ATS takes asynchronous and synchronous mode, and node i receives node j sync beacon, can adjust itselfSo that
The clock of clock after must adjusting close to node j.In order to adjustTo be compensated to drift rate, ATS need to know node i with
The ratio between drift rate between node j aij=aj/ai, but due to aiWith ajValue can not directly obtain, therefore ATS pass through it is indirect
Mode calculate aij：
Wherein：
τj(t0) for node j in t0The timestamp recorded during moment broadcast synchronization beacon；
τi,j(t0) for node i in t0Reception to node j sync beacon when the timestamp that records；
τj(t1) for node j in t1The timestamp recorded during moment broadcast synchronization beacon；
τi,j(t1) for node i in t1Reception to node j sync beacon when the timestamp that records.
Due to marking timestamp method using the MAC layer based on SFD captures, sync beacon can be sent and received in node
When detect SFD (SFD) carry out logging timestamp, the defeated delay of sync beacon can be ignored, it is believed that recipient node
It is in same time of day mark timestamp (such as τ with sending nodej(t0) and τi,j(t0) all it is in t0When marking time
Stamp).
Because formula (3) needs node i to receive the sync beacon twice from node j, therefore receive synchronization for the first time
Time stamp data τ caused by beaconi,j(t0) and τj(t0) and node j address, it is necessary to be stored among the internal memory of node i,
If calculate aij, aijIt is also required to be stored among internal memory.
Among intensive network, the neighbor node quantity of node i is very big；Once node i receives one from new
The sync beacon of neighbor node, node i must open up new memory headroom to deposit caused time stamp data, and such result is
Node i is caused to store too many time stamp data.Therefore this uncontrollable EMS memory occupation can cause distributed average synchronous calculation
Method is difficult to apply in intensive or dynamic network.
The content of the invention
It is an object of the invention to provide a kind of Distributed Wireless Sensor Networks method for synchronizing time of low memory cost, its
In overcoming each node memory in current distributed synchronization algorithm to take the problem of excessive, Distributed Time synchronism stability is being ensured
While property, the EMS memory occupation of each node is controlled, makes the radio node of limited memory can also apply in large-scale Dynamic Networks
In network and intensive distributed network.
A kind of Distributed Wireless Sensor Networks method for synchronizing time of low memory cost provided by the invention, its step are：
S1：Initialize node configuration；
S2：Sending node periodically broadcast synchronization beacon, pass through the sync beacon and historical time stamp is provided and sent
The very first time stamp recorded during nodes broadcast synchronization beacon；
S3：Releasing memory space：After sync beacon has been broadcasted, clear to send node is sent the sending node
Historical time stamp, releasing memory；
S4：Clock amendment：Receiving node receives the sync beacon of sending node broadcast, and the is obtained from sync beacon
One timestamp and historical time stamp, and the second timestamp when receiving the sync beacon to the receiving node is remembered
Record, for being modified to clock.
Preferably, in the step S1, the method for initialization node configuration is：Each initial drift rate parameter of node is set
For 1, initial offset parameter is set to 0.
Preferably, in the step S2, if first node and section point are any two adjacent node in network, the
Two nodes are as sending node, and during according to the sync beacon of periodic broadcasting second to first node, second sync beacon will add
Add the address ID for the first node that the historical time stored in the internal memory of the section point stabs and historical time stamp is corresponding；
Historical time stamp be it is upper once communicate when the first node as sending node to broadcast first to the section point same
The 3rd timestamp and the section point recorded during step beacon is remembered when receiving the first sync beacon of first node broadcast
4th timestamp of record.
Preferably, if first node and section point are any two adjacent node in network, first when communicating first
Do not include historical time corresponding with section point in the sync beacon that node is broadcasted as sending node to stab；Section point stores
Very first time stamp when its second timestamp when receiving sync beacon and the first node are in broadcast synchronization beacon, and will
The very first time stabs and second timestamp is stored as historical time stamp corresponding with the first node；It is described to communicate to enter first
Row clock amendment.
Preferably, in the step S2, the sync beacon includes：Sending node recorded when it is broadcasted first when
Between stamp, the timing parameter of sending node and sending node internal memory in the historical time stamp that is stored；The timing parameter includes
Drift rate parameter and offset parameter；
The form of the network address of the sending node is 2 bytes, and the form of the sending node timing parameter is 4 words
Section, the form of the timestamp of the sending node record is 6 bytes, is stored in the form of the historical time stamp of the sending node
For K 14 bytes, K is the number of the neighbor node of the sending node.
Preferably, in shown step S3：The sending node is after sync beacon has been broadcasted, during the history that will be sent
Between stab after occupied memory marker is " can be rewritten ", delete historical time stamp sent, discharge internal memory for new
Timestamp is stored；When storing new timestamp in the internal memory discharged, the internal memory removes the mark of " can be rewritten "
Note.
Preferably, the step of clock amendment of the receiving node in the step S4 includes：
S41：Calculate the ratio between drift rate of the receiving node；
S42：Drift rate compensation is carried out, updates the drift rate parameter of the receiving node；
S43：Migration is carried out, updates the offset parameter of the receiving node.
Preferably, the ratio between drift rate a is calculatedijFormula be：
Wherein, node i t1The receiving node at moment, node j are t1The transmission section at moment
Point；τj(t1) for node j in t1The timestamp recorded during moment broadcast synchronization beacon；τij(t1) for node i in t1Reception arrives
The timestamp recorded during the sync beacon of node j broadcast；τji(t0) for node j in t0The synchronization that reception is broadcasted to node i
The timestamp recorded during beacon；τi(t0) for node i in t0The timestamp recorded during moment broadcast synchronization beacon；
The renewal drift rate parameterFormula be：
The renewal offset parameterFormula be：
Wherein,For the drift rate parameter of node i,For node j drift rate parameter, η ∈ (0,1), η are mean parameter,
ν ∈ (0,1), ν are mean parameter, aiFor the clock crystal oscillator drift rate of node i, ajFor the j clock crystal oscillator drift rates of node, biFor
The clock skew of node i, t1For t1Moment, CiClock after being adjusted for node i, CjClock after being adjusted for node j.
Preferably, the number of the historical time stamp stored in the internal memory of any one node is up to 2K, is the K by the node
Individual neighbor node is respectively to twice of timestamp number caused by the nodes broadcast synchronization beacon.
Compared with prior art, beneficial effects of the present invention are：
(1) according to WSN distributed feature, a kind of Distributed Time synchronized algorithm of low memory cost is devised, is saved
The internal memory of point is controllable, so even among intensive network, node still can be with normal work without because low memory is led
Cause is synchronously obstructed；
(2) present invention possesses the advantages of distributed synchronization algorithm high robust and autgmentability, all nodal functions always, nothing
Reference mode, without specific topological structure, it can apply among dynamic network；
(3) present invention compensate for the drift rate of clock, therefore be offset compared to simple compensating clock, when the present invention can make
The control for a long time of clock error reduces synchronization times in lower value, reduces synchronization overhead；
(4) present invention greatly reduces uncertain prolong using the method for the MAC layer timestamp label based on SFD captures
Delay difference, drastically increase synchronization accuracy.
Brief description of the drawings
Fig. 1 is beacon transmittance process schematic diagram between two nodes of the invention；
Fig. 2 is the sync beacon data packet format schematic diagram of the present invention.
Embodiment
The invention provides a kind of Distributed Wireless Sensor Networks method for synchronizing time of low memory cost, to make the present invention
Become apparent, below in conjunction with specific embodiments and the drawings, the present invention will be further described.
A kind of Distributed Wireless Sensor Networks method for synchronizing time step of low memory cost of the present invention is：
S1：Initialize node configuration；
S2：Sending node carries out periodically broadcast synchronization beacon, records what is recorded during sending node broadcast synchronization beacon
Timestamp；
S3：Releasing memory space：Sending node after sync beacon has been broadcasted, clear to send node sent go through
History timestamp, releasing memory；
S4：Clock amendment：After receiving node receives the sync beacon of sending node broadcast, the record time of reception receives section
Point receives the timestamp recorded during the sync beacon of sending node broadcast, and clock is modified.
In node configuration step is initialized, the initial drift rate parameter of each node1 is set to, initial drift regulationIt is set to 0.
Each node can carry out broadcast synchronization beacon according to cycle T in network, as shown in figure 1, in t0Moment, in network
In, node i broadcasts a sync beacon, is contained in sync beacon：Node i delivery time (t0Moment) timestamp τi(t0)、
The timing parameter of node iAnd the address ID of node i, wherein,For drift rate adjustment parameter,Join for offset adjusted
Number.Assuming that there is no now historical time to stab data in the internal memory of node i, then other excessive datas are not added in sync beacon.
As shown in figure 1, τi(t0) for node i in t0The timestamp recorded during moment broadcast synchronization beacon；τj,i(t0) it is section
Point j is in t0Reception to node i sync beacon when the timestamp that records；τj(t1) for node j in t1Moment broadcast synchronization is believed
The timestamp of timestamp record；τi,j(t1) for node i in t1Reception to node j sync beacon when the timestamp that records.
Fig. 2 is the data packet format schematic diagram of sync beacon, wherein, the SrcID of 2 bytes is the network of sending node
Location；The SrcDrift of 4 bytes and 4 byte SrcOffset is sending node timing parameterThe SrcClk of 6 bytes is
The timestamp of sending node record；The PrevData of K 14 bytes is the historical time stamp for being stored in sending node.Should
In PrevData internal memory, timestamp caused by full K neighbor node can record.
Sending node records a timestamp in its broadcast synchronization beacon, and receiving node records one in its time of reception
Timestamp, sending node record timestamp be sent to receiving node, make receiving node once communicate when obtain two when
Between stab data.Any one node can at most store timestamp caused by K neighbor node, then the time caused by K neighbor node
Stamp data amount check is at most 2K.
In t0At the moment, when receiving node is node j, sending node is node i, and node j have received the synchronous letter of node i
Mark, records timestamp τji(t0), inquired about, except node i is in t in the sync beacon for finding to receive0Moment broadcast is same
Walk the timestamp τ recorded during beaconi(t0), without other available timestamps.
Assuming that node j internal memory is available free (not recording timestamp caused by full K neighbor node), then two timestamps
[τji(t0),τi(t0)] and the address ID of node i can all be stored in node j internal memory.
In t1At the moment, when sending node is node j, receiving node is node i, during node j broadcast synchronization beacons, synchronous letter
The two historical times stamp [τ in node j internal memory will be added in markji(t0),τi(t0)] (node j is in t0Reception arrives
The timestamp τ recorded during the sync beacon of node i broadcastji(t0) and node i in t0Recorded during moment broadcast synchronization beacon when
Between stab τi(t0)) and corresponding node i node ID.
Sending node stabs [τ after sync beacon has been sent, by sent two historical timesji(t0),τi(t0)] shared
According to memory block be labeled as " can be rewritten ", delete historical time stamp that this is sent, discharge internal memory so that new timestamp enters
Row storage；When storing new timestamp in the internal memory discharged, the internal memory removes the mark of " can be rewritten ".
If node i receives the sync beacon of node j broadcast, node i obtains node j in t first1Moment broadcast synchronization is believed
The timestamp τ of timestamp recordj(t1) and node i in t1The timestamp τ recorded during the sync beacon that reception is broadcasted to node jij
(t1) the two timestamps [τj(t1),τij(t1)], two historical times for then obtaining node j again in sync beacon stab
[τji(t0),τi(t0)]。
Therefore node i can directly obtain four timestamp [τ in this time communication processj(t1),τij(t1)]、[τji
(t0),τi(t0)], therefore the ratio between drift rate a can be calculated by formula (4)ij：
Wherein, node i t1The receiving node at moment, node j are t1The sending node at moment；
τj(t1) for node j in t1The timestamp recorded during moment broadcast synchronization beacon；τij(t1) for node i in t1Moment
The timestamp recorded during the sync beacon for receiving node j broadcast；τji(t0) for node j in t0Reception is broadcasted to node i
Sync beacon when the timestamp that records；τi(t0) for node i in t0The timestamp recorded during moment broadcast synchronization beacon.
Calculate the ratio between drift rate aijAfterwards, node i carries out drift rate compensation, updates drift rate parameter by formula (5)
After drift rate compensation, node i carries out migration to update offset parameter by formula (6)
Wherein,For the drift rate parameter of node i,For node j drift rate parameter, η ∈ (0,1), η are average ginseng
Number, ν ∈ (0,1), ν are mean parameter, aiFor the clock crystal oscillator drift rate of node i, ajFor the j clock crystal oscillator drift rates of node, bi
For the clock skew of node i, t1For t1Moment, CiClock after being adjusted for node i, CjClock after being adjusted for node j,Just
Beginningization parameter is 1,Initiation parameter be 0.
In above-mentioned two node i and j intercommunication, two timestamp [τ of node j transmissionsji(t0),τi(t0)] quilt
Node i make use of, therefore [τji(t0),τi(t0)] even if being deleted, it there will not be too big influence, therefore node j can should [τji
(t0),τi(t0)] it is labeled as " can be rewritten ".If node j receives second of sync beacon from node i, and in internal memory
Two historical times stab [τji(t0),τi(t0)] be not yet deleted, then node j still can calculate a using above-mentioned timestampij,
Use formula (3).
Above-mentioned formula (5) and formula (6) are the embodiments of average algorithm, and node i joins the drift rate parameter of itself and skew
Number is adjusted to the value being more nearly with node j.Without loss of generality, clock constantly can be adjusted to itself and neighbor node by node i
Approximate average.Therefore for whole network, the deviation of each node and other nodes can be less and less, by certain
After cycle, the parameter of the clock of each node can be gradually restrained so that the clock of the whole network reaches consistent.
Compared with traditional distributed algorithm ATS, the two-way communication in the present invention between two nodes will cause one of them
Node enters the amendment of row clock, without waiting the sync beacon received twice from same node.And complete two-way
The time of letter process is less than a cycle T, for dynamic network interior joint Encounter Time it is shorter in the case of, the present invention can still protect
Demonstrate,prove certain synchronous efficiency.
The storage size of node, which is already artificially limited to, stores up to time stamp data caused by K neighbor node, and K can basis
Node memory actual conditions are adjusted.In the case that node storage is full, the sync beacon of new node is received, first
Whether there is memory block to be marked as " can be rewritten " inquiry, if so, then data will be replaced with new data in the memory block, if
Nothing, then new data will be rejected.
Although present disclosure is discussed in detail by above preferred embodiment, but it should be appreciated that above-mentioned
Description is not considered as limitation of the present invention.After those skilled in the art have read the above, for the present invention's
A variety of modifications and substitutions all will be apparent.Therefore, protection scope of the present invention should be limited to the appended claims.
Claims (9)
1. a kind of Distributed Wireless Sensor Networks method for synchronizing time of low memory cost, it is characterised in that its step is：
S1：Initialize node configuration；
S2：Sending node periodically broadcast synchronization beacon, pass through the sync beacon and historical time stamp and sending node are provided
The very first time stamp recorded during broadcast synchronization beacon；
S3：Releasing memory space：The sending node after sync beacon has been broadcasted, clear to send node sent go through
History timestamp, releasing memory；
S4：Clock amendment：Receiving node receives the sync beacon of the sending node broadcast, when obtaining first from sync beacon
Between stamp and historical time stamp, and the second timestamp when receiving the sync beacon to the receiving node records, and uses
To be modified to clock.
2. a kind of Distributed Wireless Sensor Networks method for synchronizing time of low memory cost as claimed in claim 1, its feature
It is,
In the step S1, the method for initialization node configuration is：
Each initial drift rate parameter of node is set to 1, and initial offset parameter is set to 0.
3. a kind of Distributed Wireless Sensor Networks method for synchronizing time of low memory cost as claimed in claim 1, its feature
It is,
In the step S2,
If first node and section point are any two adjacent node in network,
Section point is as sending node, during according to the sync beacon of periodic broadcasting second to first node, the described second synchronous letter
The historical time stored in the internal memory for adding the section point stamp and the historical time are stabbed corresponding first node by mark
Address ID；
Historical time stamp be it is upper once communicate when the first node broadcast the to the section point as sending node
The 3rd timestamp recorded during one sync beacon and the section point receive the first sync beacon of first node broadcast
Shi Jilu the 4th timestamp.
4. a kind of Distributed Wireless Sensor Networks method for synchronizing time of low memory cost as claimed in claim 1, its feature
It is,
If first node and section point are any two adjacent node in network,
History corresponding with section point is not included in the sync beacon that first node is broadcasted as sending node when communicating first
Timestamp；Section point stores its second timestamp when receiving sync beacon and the first node in broadcast synchronization beacon
When very first time stamp, and the very first time is stabbed and second timestamp is stored as historical time corresponding with the first node
Stamp；
It is described to communicate first without clock amendment.
5. a kind of Distributed Wireless Sensor Networks method for synchronizing time of low memory cost as claimed in claim 1, its feature
It is,
In the step S2, the sync beacon includes：The very first time that sending node is recorded when it is broadcasted stabs, sends section
The historical time stamp stored in the timing parameter of point and the internal memory of sending node；
The timing parameter includes drift rate parameter and offset parameter；
The form of the network address of the sending node is 2 bytes, and the form of the sending node timing parameter is 4 bytes, institute
The form for stating the timestamp of sending node record is 6 bytes, and the form for being stored in the historical time stamp of the sending node is K
14 bytes, K are the numbers of the neighbor node of the sending node.
6. a kind of Distributed Wireless Sensor Networks method for synchronizing time of low memory cost as claimed in claim 1, its feature
It is,
In shown step S3：
For the sending node after sync beacon has been broadcasted, being by the occupied memory marker of the historical time sent stamp " can
It is rewritten " after, the historical time stamp sent is deleted, discharges internal memory so that new timestamp is stored；
When storing new timestamp in the internal memory discharged, the internal memory removes the mark of " can be rewritten ".
7. a kind of Distributed Wireless Sensor Networks method for synchronizing time of low memory cost as claimed in claim 1, its feature
It is,
The step of clock amendment of receiving node in the step S4, includes：
S41：Calculate the ratio between drift rate of the receiving node；
S42：Drift rate compensation is carried out, updates the drift rate parameter of the receiving node；
S43：Migration is carried out, updates the offset parameter of the receiving node.
8. a kind of Distributed Wireless Sensor Networks method for synchronizing time of low memory cost as claimed in claim 7, its feature
It is,
Calculate the ratio between drift rate aijFormula be：
<mrow>
<msub>
<mi>a</mi>
<mrow>
<mi>i</mi>
<mi>j</mi>
</mrow>
</msub>
<mo>=</mo>
<mfrac>
<mrow>
<msub>
<mi>&tau;</mi>
<mi>j</mi>
</msub>
<mrow>
<mo>(</mo>
<msub>
<mi>t</mi>
<mn>1</mn>
</msub>
<mo>)</mo>
</mrow>
<mo>-</mo>
<msub>
<mi>&tau;</mi>
<mrow>
<mi>j</mi>
<mo>,</mo>
<mi>i</mi>
</mrow>
</msub>
<mrow>
<mo>(</mo>
<msub>
<mi>t</mi>
<mn>0</mn>
</msub>
<mo>)</mo>
</mrow>
</mrow>
<mrow>
<msub>
<mi>&tau;</mi>
<mrow>
<mi>j</mi>
<mo>,</mo>
<mi>i</mi>
</mrow>
</msub>
<mrow>
<mo>(</mo>
<msub>
<mi>t</mi>
<mn>1</mn>
</msub>
<mo>)</mo>
</mrow>
<mo>-</mo>
<msub>
<mi>&tau;</mi>
<mi>i</mi>
</msub>
<mrow>
<mo>(</mo>
<msub>
<mi>t</mi>
<mn>0</mn>
</msub>
<mo>)</mo>
</mrow>
</mrow>
</mfrac>
<mo>;</mo>
</mrow>
Wherein, node i t1The receiving node at moment, node j are t1The sending node at moment；
τj(t1) for node j in t1The timestamp recorded during moment broadcast synchronization beacon；τij(t1) for node i in t1Reception arrives
The timestamp recorded during the sync beacon of node j broadcast；τji(t0) for node j in t0The synchronization that reception is broadcasted to node i
The timestamp recorded during beacon；τi(t0) for node i in t0The timestamp recorded during moment broadcast synchronization beacon；
The renewal drift rate parameterFormula be：
<mrow>
<msub>
<mover>
<mi>a</mi>
<mo>^</mo>
</mover>
<mi>i</mi>
</msub>
<mrow>
<mo>(</mo>
<msub>
<mi>t</mi>
<mn>1</mn>
</msub>
<mo>)</mo>
</mrow>
<msub>
<mi>a</mi>
<mi>i</mi>
</msub>
<mo>:</mo>
<mo>=</mo>
<mi>&eta;</mi>
<msub>
<mover>
<mi>a</mi>
<mo>^</mo>
</mover>
<mi>i</mi>
</msub>
<mrow>
<mo>(</mo>
<msub>
<mi>t</mi>
<mn>1</mn>
</msub>
<mo>)</mo>
</mrow>
<msub>
<mi>a</mi>
<mi>i</mi>
</msub>
<mo>+</mo>
<mrow>
<mo>(</mo>
<mn>1</mn>
<mo>-</mo>
<mi>&eta;</mi>
<mo>)</mo>
</mrow>
<msub>
<mover>
<mi>a</mi>
<mo>^</mo>
</mover>
<mi>j</mi>
</msub>
<mrow>
<mo>(</mo>
<msub>
<mi>t</mi>
<mn>1</mn>
</msub>
<mo>)</mo>
</mrow>
<msub>
<mi>a</mi>
<mi>j</mi>
</msub>
<mo>;</mo>
</mrow>
The renewal offset parameterFormula be：
<mrow>
<msub>
<mover>
<mi>b</mi>
<mo>^</mo>
</mover>
<mi>i</mi>
</msub>
<mo>:</mo>
<mo>=</mo>
<msub>
<mover>
<mi>b</mi>
<mo>^</mo>
</mover>
<mi>i</mi>
</msub>
<mo>+</mo>
<mrow>
<mo>(</mo>
<mn>1</mn>
<mo>-</mo>
<mi>v</mi>
<mo>)</mo>
</mrow>
<mrow>
<mo>(</mo>
<msub>
<mi>C</mi>
<mi>j</mi>
</msub>
<mo>-</mo>
<msub>
<mi>C</mi>
<mi>i</mi>
</msub>
<mo>)</mo>
</mrow>
<mo>;</mo>
</mrow>
Wherein,For the drift rate parameter of node i,For node j drift rate parameter, η ∈ (0,1), η are mean parameter, ν ∈
(0,1), ν are mean parameter, aiFor the clock crystal oscillator drift rate of node i, ajFor the j clock crystal oscillator drift rates of node, biFor node
I clock skew, t1For t1Moment, CiClock after being adjusted for node i, CjClock after being adjusted for node j.
9. a kind of Distributed Wireless Sensor Networks method for synchronizing time of low memory cost as claimed in claim 1, its feature
It is,
The number of the historical time stamp stored in the internal memory of any one node is up to 2K, is the K neighbor node by the node
Respectively to twice of timestamp number caused by the nodes broadcast synchronization beacon.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710574605.5A CN107395308B (en) | 2017-07-14 | 2017-07-14 | A kind of Distributed Wireless Sensor Networks method for synchronizing time of low memory overhead |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710574605.5A CN107395308B (en) | 2017-07-14 | 2017-07-14 | A kind of Distributed Wireless Sensor Networks method for synchronizing time of low memory overhead |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107395308A true CN107395308A (en) | 2017-11-24 |
| CN107395308B CN107395308B (en) | 2019-04-09 |
Family
ID=60339754
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710574605.5A Active CN107395308B (en) | 2017-07-14 | 2017-07-14 | A kind of Distributed Wireless Sensor Networks method for synchronizing time of low memory overhead |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107395308B (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108599887A (en) * | 2018-04-24 | 2018-09-28 | 新华三技术有限公司 | A kind of time difference computational methods and forwarding unit |
| CN109041202A (en) * | 2018-08-02 | 2018-12-18 | 陕西集星合智防务科技有限公司 | A kind of distributed clock synchronized algorithm suitable for Ad hoc network |
| CN110191506A (en) * | 2018-12-06 | 2019-08-30 | 杭州微萤科技有限公司 | A kind of synchronous method of list zone location base station and positioning terminal |
| WO2022021010A1 (en) * | 2020-07-27 | 2022-02-03 | Shenzhen University | Method and apparatus for clock synchronization in wireless network |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101232514A (en) * | 2008-01-24 | 2008-07-30 | 创新科存储技术（深圳）有限公司 | Metadata synchronization method of network additional memory node and network additional memory node |
| US20100020909A1 (en) * | 2008-07-24 | 2010-01-28 | Jung Hong-Kyu | Synchronizing apparatus and method in packet network |
| CN103812589A (en) * | 2012-11-09 | 2014-05-21 | 中国科学院沈阳计算技术研究所有限公司 | Time synchronization method based on double ring bus |
| CN104753622A (en) * | 2013-12-25 | 2015-07-01 | 中国科学院沈阳自动化研究所 | Low-overhead time synchronization method based on receivers under start network |
-
2017
- 2017-07-14 CN CN201710574605.5A patent/CN107395308B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101232514A (en) * | 2008-01-24 | 2008-07-30 | 创新科存储技术（深圳）有限公司 | Metadata synchronization method of network additional memory node and network additional memory node |
| US20100020909A1 (en) * | 2008-07-24 | 2010-01-28 | Jung Hong-Kyu | Synchronizing apparatus and method in packet network |
| CN103812589A (en) * | 2012-11-09 | 2014-05-21 | 中国科学院沈阳计算技术研究所有限公司 | Time synchronization method based on double ring bus |
| CN104753622A (en) * | 2013-12-25 | 2015-07-01 | 中国科学院沈阳自动化研究所 | Low-overhead time synchronization method based on receivers under start network |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108599887A (en) * | 2018-04-24 | 2018-09-28 | 新华三技术有限公司 | A kind of time difference computational methods and forwarding unit |
| CN109041202A (en) * | 2018-08-02 | 2018-12-18 | 陕西集星合智防务科技有限公司 | A kind of distributed clock synchronized algorithm suitable for Ad hoc network |
| CN110191506A (en) * | 2018-12-06 | 2019-08-30 | 杭州微萤科技有限公司 | A kind of synchronous method of list zone location base station and positioning terminal |
| WO2022021010A1 (en) * | 2020-07-27 | 2022-02-03 | Shenzhen University | Method and apparatus for clock synchronization in wireless network |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107395308B (en) | 2019-04-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107395308B (en) | A kind of Distributed Wireless Sensor Networks method for synchronizing time of low memory overhead | |
| CN106209289B (en) | A kind of moonlet self-organizing network method for synchronizing time | |
| CN104053223A (en) | Low-power wireless sensor network time synchronization method | |
| CN101083523B (en) | Method and device for realizing integrated time stamp clock synchronous phase-locked loop | |
| CN104519563B (en) | One kind layering wireless sensor network time synchronization method | |
| CN107949047A (en) | Reduce the wireless sensor network uniformity method for synchronizing time of Internet traffic | |
| Gong et al. | CESP: A low-power high-accuracy time synchronization protocol | |
| Huang et al. | Long term and large scale time synchronization in wireless sensor networks | |
| CN105743598B (en) | A kind of Industrial Ethernet clock synchronizing method and system | |
| CN101977104A (en) | IEEE1588 based accurate clock synchronization protocol system and synchronization method thereof | |
| CN101562489A (en) | Method for time synchronization in wireless sensor network | |
| CN103546868B (en) | A kind of method for synchronizing time of wireless sensor network, network system and node | |
| CN105188126A (en) | Distributed multi-hop wireless network clock synchronization method based on mean field | |
| CN109548135A (en) | A kind of wireless network time synchronous method of optimization | |
| CN105721095B (en) | A kind of synchronous improved method of substation equipment clock | |
| CN102196554A (en) | Method for realizing average clock synchronization of wireless sensor network through cluster averaging | |
| Tian et al. | Delay compensation-based time synchronization under random delays: Algorithm and experiment | |
| CN101174939A (en) | Wireless meshed network low-spending high-precision time synchronization process for industry monitoring | |
| Gong et al. | Temperature compensated Kalman distributed clock synchronization | |
| CN103957591A (en) | Node pair based wireless sensor network time synchronization method | |
| CN105491656B (en) | A kind of lightweight method for synchronizing time towards extensive ad hoc network | |
| CN106533602A (en) | ATS-protocol-based time synchronization method of hierarchical network | |
| Seth et al. | Energy efficient timing-sync protocol for sensor network | |
| CN108924922A (en) | A kind of chain synchronous method synchronization time of WSN cluster type topology | |
| Lv et al. | Simulation and performance analysis of the ieee1588 ptp with kalman filtering in multi-hop wireless sensor networks |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |