CN102045833B - Communication synchronization method among wireless transceivers in wireless sensor network (WSN) - Google Patents
Communication synchronization method among wireless transceivers in wireless sensor network (WSN) Download PDFInfo
- Publication number
- CN102045833B CN102045833B CN201110002614XA CN201110002614A CN102045833B CN 102045833 B CN102045833 B CN 102045833B CN 201110002614X A CN201110002614X A CN 201110002614XA CN 201110002614 A CN201110002614 A CN 201110002614A CN 102045833 B CN102045833 B CN 102045833B
- Authority
- CN
- China
- Prior art keywords
- pulse
- phase
- radio
- generating circuit
- signal
- 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.)
- Expired - Fee Related
Links
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D30/00—Reducing energy consumption in communication networks
- Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks
Landscapes
- Synchronisation In Digital Transmission Systems (AREA)
- Mobile Radio Communication Systems (AREA)
Abstract
The invention discloses a host synchronization method under the conditions of layered or cluster characteristics as well as host nodes (or anchor nodes) and low-consumption label nodes, and a communication circuit for simplifying the label nodes, which are applied to a wireless sensor network (WSN). In the method, by means of the feedback control process between a host and a label receiver, the phase of a modulation signal received by the label receiver is consistent with the local phase, and only few feedback times are required, thus a small amount of energy is consumed by the label nodes. The invention further discloses a two-step capture method; and by means of the method, higher capture speed can be acquired without increasing the complexity of the label receiver.
Description
Technical field
The present invention relates to radio sensing network, the synchronous method of specifically communicating by letter between radio receiving-transmitting unit.
Background technology
Radio sensing network (WSN) technology provides for a long time, on a large scale, multiposition point and large capacity information with information gathering, communicate by letter and processing.Radio sensing network is comprised of tag sensor node and host node (or being called cluster knot point, anchor node), and label node sends to the master control point by communication and network technology with heat transfer agent and carries out information fusion.On the one hand label node need to possess efficient and real-time interactive communication means, also requires on the other hand sensing node to keep extremely low power consumption guaranteeing non-maintaining work for a long time, and possesses less volume and complexity.
Most extensive WSN adopt layering or clustering architecture, and the main controlled node in bunch has stronger communication and information processing ability.The sensing label node is mainly completed the function of information gathering, is operated in low-power consumption, even under the resting state of extremely low power dissipation.Realize that node wakes up, and interactive communication with it, need each label node to possess complete wireless communication module under normal condition.Only the wireless passive type sensing network of extremely low power dissipation (WPSN) of need cluster knot point transmitting power is subject to the favor of sensing network research field, excite by the main frame radio-frequency power, closely MIN power of communications needs of label node can be provided, but still more difficult full scale communication distance, interactive communication, label node complexity and to the requirement of traffic rate.
Capturing carrier, bit synchronization and net synchronizing process are to complete the necessary condition of radio sensing network data communication, and synchronous precision is restricting the quality of input.Current WSN adopts the passive method of catching of receiver habitual in radio communication, its advantage is that acquisition speed is fast and synchronization accuracy is good, but its shortcoming is to require receiver to possess controlled clock (for example digital controlled oscillator NCO), or signal sampling and processing capacity at a high speed, this causes the complexity of circuit and higher power consumption.
More method has been arranged by the upper layer network technology in this WSN technical field, such as the optimization route etc., reduced the power consumption of sensing node.But this also brings simultaneously, and interactive information is many, Route Selection is processed complicated problem.
Summary of the invention
The object of the invention is to the physical layer communication angle from utmost point low complex degree and power consumption, propose a kind of host node synchronous method that is different from conventional wireless communication synchronization acquistion mechanism, and provide a kind of two-step capturing algorithm of Rapid timing acquisition.
Consider that in WSN, a large amount of tag sensor nodes do not need high-speed synchronous catch and communicate by letter, and be the communication of burst type small data quantity, simultaneously, the cluster knot point of WSN (or claiming host node, anchor node) can need not too much to consider the problem of power consumption and complexity, and possess completely, conventional radio receiving-transmitting unit function, stronger signal detection performance is just arranged, and label node is opposite.For this uneven link, the present invention adopts a kind ofly has the main frame synchronous method of feedback to realize that main frame is to the communication of label node.
the synchronous method of communicating by letter between radio receiving-transmitting unit of the present invention, comprise host side and receiver end, and wireless transmitter, the host side setting can produce burst pulse and possess the pulse-generating circuit A of waveform signal that can the fine resolution phase place, connecting radio frequency after A amplifies and transmitting antenna, connecting successively the phase control function unit B and can carry out order before pulse-generating circuit A and increasing progressively, order is successively decreased, the phase place stepping searching algorithm functional unit C of the searching algorithm of fixing or variable step size phase place, and in order to receive the radio receiving unit F of feedback acknowledgment signal, the receiver end setting can be correlated with or the phase discriminator D of irrelevant pulse signal detection and thresholding comparison and the latter linked feedback circuit E that can the feedback acknowledgment signal be launched by Radio Link of phase discriminator D, radio frequency is set in feedback circuit E amplifies and transmitting antenna.
Wherein, host side refers to possess transmitter, anchor node or the base station of stronger communication and disposal ability and higher-energy dispensing; The phase control function unit B is voltage controlled oscillator, controllable delay line or digital controlled oscillator.Receiver end refers to have wireless receiver, label or the sensing node of simple communication detectability and modulate emission ability; Phase discriminator D is matched filter, difference detector, envelope detector or energy testing apparatus.
Searching algorithm functional unit C adopts two step search procedures, and the first step adopts large pulse width T
1Carry out slightly synchronously, second step changes pulse duration into T in the large pulse width range of locking
p, T
p=T
1, at T
1Carry out the acquisition search of identical process in scope.
If radio receiving-transmitting unit has identical pulse signal cycle T and pulse width T
pUtilize the General Principle of reaction type synchronization acquistion, phase-locked loop for example, difference is: the phase discrimination function that only utilizes the phase discriminator settling signal at receiver end, and error signal is processed and the adjustment of recurrent pulse phase place is transferred to host side (host node of WSN) and completed, the feedback of phase discrimination signal is achieved by the reception of the receiving element in host side by radio transmission.Only need to guarantee less feedback, just can guarantee to receive the less power consumption of terminal.
The synchronous method of communicating by letter between radio receiving-transmitting unit in radio sensing network of the present invention.Can adopt multiple recurrent pulse modulation signal in concrete enforcement, TH-PPM for example, PAM modulation etc.
The main frame synchronization acquistion basic principle that proposes in the present invention and process can illustrate with this iteration difference equation.
For reducing the host side synchronization acquistion time, the present invention further proposes two step main frame catching methods, and its acquisition procedure is identical with one-step method.The first step adopts large pulse width T
1Carry out slightly synchronously, second step changes pulse duration into T in the large pulse width range of locking
p, T
p=T
1, at T
1Carry out the acquisition search of identical process in scope.Adopt the similar search by half of two-step capturing principle, can larger raising acquisition speed, and very little to the complexity increase of receiver end.
The invention has the advantages that: by the signal in synchronizing process being processed and position adjusting function and circuit are transferred to host side, complexity and reduction power consumption that can the simplified receiver physical layer communication mutually.This method of synchronization is suitable for communicating by letter of WSN label node that volume and power consumption are had higher requirements.Can reduce complexity and the power consumption of label node by physical-layer techniques.
Description of drawings
Fig. 1 is that in the present invention, each functional module connects block diagram and radio propagation channel propagation schematic diagram.
Embodiment
As shown in Figure 1.Wherein in the square frame of left side, the phase discriminator detection signal on receiver end is necessary, also comprises a feedback signal transmitter unit, so complexity has been reduced to minimum level; In the square frame of right side, the host side circuit comprises four modules: cycle counter, digital controlled oscillator (NCO) and recurrent pulse generator that main frame radio receiving unit, feedback acknowledgment signal trigger.Middle two squares represent front, reverse radio propagation channel and the time-delay that therefore brings, and the square that is connected with the host side pulse-generating circuit in block diagram identifies forward direction (main frame is to the receiver direction) channel and propagation delay D thereof
fwd, the square that is connected with feedback acknowledgment transmitter unit in receiver end identifies oppositely (receiver is to the main frame direction) channel and propagation delay D thereof
Fdbk, this time delay also can think on principle comprised before the reverse time delay processed separately of transceiver.Q in Fig. 1 (i) refers at i constantly, the pulse signal phase place that label receiver receives, q
0Refer to the local oscillator phase place of label receiver.
Above feedback procedure block diagram can be with concrete phase difference the Representation Equation:
q(i)＝q(i-1)+DqG[q(i-D)-q
0] (1)
In formula (1), G (*) function is gate function, and its expression formula is as shown in (2); Dq is that phase step is adjusted the factor, and this acquisition procedure it should be noted that the value of Dq not only affects the precision of this feedback capture loop, and affects the stability of loop.Under certain loop time delay D condition, larger Dq can cause loop can't enter trapped state.In formula (1), D is that main frame is to label node propagated forward time delay D
fwdWith label node feedback delay D
FdbkAnd, T
pBe the ultra-narrow pulse width, T is pulse signal cycle.
Host side is host transmitter, setting can produce burst pulse and possess the pulse-generating circuit A of waveform signal that can the fine resolution phase place, connecting radio frequency after A amplifies and transmitting antenna (not drawing in figure), connecting successively the phase control function unit B before pulse-generating circuit A, the cycle count accumulator C that can sequentially increase progressively, successively decrease, fixing or variable step size is searched for, and in order to receive the radio receiving unit F of feedback acknowledgment signal; Receiver end is label receiver, setting can be correlated with or irrelevant pulse signal detection and thresholding phase discriminator D relatively, and the latter linked radiating circuit E that can the feedback acknowledgment signal be launched by Radio Link of phase discriminator D, comprised in the E circuit wherein that radio frequency amplifies and transmitting antenna partly (not drawing in figure).
Set the pulse generator that host transmitter and label receiver have same period.Because two step main frame synchronization acquiring methods are based on single step main frame synchronization scenario, below at first list the implementation step of single step main frame, then list the two-step capturing process, but the content that partial content citation single step is caught.
The single step main frame is synchronous:
(1) host node is by pulse-generating circuit A, launch periodic pulse signal by wireless channel to label node, impulse phase is the main frame random initial phase, also implicit supporting with it radio frequency amplifying circuit and the antenna etc. of comprising that the emission of pulse-generating circuit A output pulse signal matches;
(2) in the label receiver node, phase discriminator D carries out coherent detection to received signal in its any local oscillator phase place, if correlated sampling output is greater than a given amplitude thresholding A
T(A
TFibrous root border reception signal factually is strong and weak definite), synchronization acquistion is completed in explanation, and by feedback acknowledgment signal transmission circuit E, to host node transmitting feedback confirmation signal, this feedback signal can be self-defining any discernible signal by reverse wireless channel; If instead relevant output amplitude is less than thresholding A
T, in label receiver, E does not do any action;
(3) host node is after the multiply periodic pulse signal of emission, and receiving element F all do not receive under the feedback acknowledgment signal conditioning, and cycle count accumulator C controls the phase place that digital controlled oscillator B increases progressively or reduce the transmitted pulse signal, and adjusting step-length is the corresponding T of Dq(
Dq=DqT/2 π≤T
p), by the phase place after this new adjustment, pulse-generating circuit A continues the emission periodic pulse signal;
(4) if host node is not received feedback yet, by each cell operation mode in (3), order increases progressively/reduces phase place Dq, and pulse-generating circuit A continues the emission recurrent pulse;
(5) when host side receiving element F receives the feedback acknowledgment signal, the calculating that stops search of cycle count accumulator C unit, thereby make digital controlled oscillator B stop adjusting phase place, in host node, the current impulse phase of pulse-generating circuit A output is the locking phase position, and synchronization acquistion is completed.Host node can be by this phase modulated signal to target labels node transfer information data.
The main frame synchronization acquistion of two steps:
(1) establishing the minimum adjustment of pulse phase step is Dq, and corresponding adjustment time delay is T
DqIn host node, the pulse duration of emission is set is T to pulse-generating circuit A
1T
pIf q=T/T
Δ θ, q
1Be the result that q rounds up, can prove and work as T
1=q
1* T
Δ θIn time, can obtain minimum average B configuration and catches duration.Phase search unit cycle count accumulator C adjusts pulse position step-length T by digital controlled oscillator B, pulse-generating circuit A increasing or decreasing
1(equivalence is phase step Δ θ
1=2 π T
1/ T), the hunting zone is pulse period T.In label node, the upper local coherent pulse width that loads of phase discriminator D is still T
p, acquisition procedure and above single step are caught identical;
(2) complete after the first step catches, the pulse-generating circuit A of host side and digital controlled oscillator B unit are in catches lock-out state, and phase stabilization is at q
1In host node, to reset fire pulse width be T to pulse-generating circuit A
p, digital controlled oscillator B and cycle count accumulator C are controlled increasing or decreasing adjustment phase step from Dq
1Be revised as the corresponding T of Dq(
Dq=DqT/2 π≤T
p), the whole cycle with the hunting zone from the first step is revised as [q
1, q
1+ 2 π T
1/ T], the coherent pulse width that on label node, phase discriminator D loads is still T
p, acquisition procedure and single step are caught identical.Catch the main frame phase place when completing, i.e. the phase place of pulse-generating circuit A output is locking phase.
Claims (5)
1. the synchronous method of communicating by letter between radio receiving-transmitting unit in radio sensing network, it is characterized in that: the host side setting can produce burst pulse and possess the pulse-generating circuit A of waveform signal that can the fine resolution phase place, connecting radio frequency after A amplifies and transmitting antenna, connecting successively the phase control function unit B before pulse-generating circuit A and can carry out that order increases progressively, order is successively decreased, the phase place stepping searching algorithm functional unit C of the searching algorithm of fixing or variable step size phase place, and in order to receive the radio receiving unit F of feedback acknowledgment signal; The receiver end setting can be correlated with or the phase discriminator D of irrelevant pulse signal detection and thresholding comparison and the latter linked feedback circuit E that can the feedback acknowledgment signal be launched by Radio Link of phase discriminator D, radio frequency is set in feedback circuit E amplifies and transmitting antenna;
Synchronous process comprises:
(1) host side by the periodic pulse signal that pulse-generating circuit A produces random initial phase, is launched to receiver end by wireless channel;
(2) the phase discriminator D in receiver end carries out coherent detection to received signal in its any local oscillator phase place, if sampling output is greater than a given amplitude thresholding
, complete synchronization acquistion, and by the feedback circuit E in receiver end, by reverse wireless channel to host node transmitting feedback confirmation signal; If instead the sampling output amplitude less than
, the feedback circuit E in receiver end does not do any action;
(3) host side receiving element F does not all receive under the feedback acknowledgment signal conditioning, and searching algorithm functional unit C control phase is controlled the phase place of functional unit B increasing or decreasing transmitted pulse signal, adjusts step-length and is
, correspondence
, by phase place and the step-length after this new adjustment, pulse-generating circuit A continues the emission periodic pulse signal;
(4) when host side receiving element F receives the feedback acknowledgment signal, searching algorithm functional unit C, phase control function unit B quit work, and in host side, the current impulse phase of pulse-generating circuit A output is the locking phase position, completes synchronization acquistion.
2. the synchronous method of communicating by letter between radio receiving-transmitting unit in radio sensing network according to claim 1 is characterized in that: synchronous process steps (3) specifically comprises following process:
(1) establishing the pulse position step-length is
, the minimum phase step of adjusting of pulse is
, corresponding adjustment time delay is
,
,
Be
The result that rounds up is got
, in host side, the pulse duration of emission is set is Tp≤T1 to pulse-generating circuit A, searching algorithm functional unit C control phase is controlled functional unit B, pulse-generating circuit A increasing or decreasing is adjusted the pulse position step-length
, equivalence is phase step
, the hunting zone is the pulse period
, in receiver end, the upper local coherent pulse width that loads of phase discriminator D is still
, carry out synchronization acquistion;
(2) then, the pulse-generating circuit A of host side and phase control function unit B locking phase are stabilized in
In host side, pulse-generating circuit A resets fire pulse width and is
, searching algorithm functional unit C control phase is controlled functional unit B increasing or decreasing adjustment phase step and is
, correspondence
, the whole cycle T with the hunting zone from the above-mentioned first step is revised as
, the coherent pulse width that on receiver end, phase discriminator D loads is still
, carry out synchronization acquistion.
3. the synchronous method of communicating by letter between radio receiving-transmitting unit in radio sensing network according to claim 1 is characterized in that: host side refers to possess transmitter, anchor node or the base station of stronger communication and disposal ability and higher-energy dispensing; The phase control function unit B is voltage controlled oscillator, controllable delay line or digital controlled oscillator.
4. the synchronous method of communicating by letter between radio receiving-transmitting unit in radio sensing network according to claim 1 is characterized in that: receiver end refers to have wireless receiver, label or the sensing node of simple communication detectability and modulate emission ability; Phase discriminator D is matched filter, difference detector, envelope detector or energy testing apparatus.
5. the synchronous method of communicating by letter between radio receiving-transmitting unit in radio sensing network according to claim 1 and 2 is characterized in that: searching algorithm functional unit C adopts two step search procedures, and the first step adopts large pulse duration
Carry out slightly synchronously, second step changes pulse duration in the large pulse width range of locking
, Tp≤T1,
Carry out the acquisition search of identical process in scope.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201110002614XA CN102045833B (en) | 2011-01-07 | 2011-01-07 | Communication synchronization method among wireless transceivers in wireless sensor network (WSN) |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201110002614XA CN102045833B (en) | 2011-01-07 | 2011-01-07 | Communication synchronization method among wireless transceivers in wireless sensor network (WSN) |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102045833A CN102045833A (en) | 2011-05-04 |
| CN102045833B true CN102045833B (en) | 2013-05-15 |
Family
ID=43911459
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201110002614XA Expired - Fee Related CN102045833B (en) | 2011-01-07 | 2011-01-07 | Communication synchronization method among wireless transceivers in wireless sensor network (WSN) |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102045833B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10440450B2 (en) | 2016-07-14 | 2019-10-08 | Massachusetts Institute Of Technology | System and methods for dynamic power usage and data transfer rate management in a sensor network |
| CN109257834B (en) * | 2018-09-17 | 2021-08-20 | 广州市特沃能源管理有限公司 | Networking method of mesh wireless sensor network based on Thread protocol |
| CN109765583B (en) * | 2019-03-04 | 2021-06-15 | 华通信安(北京)科技发展有限公司 | Clock synchronization method based on GNSS receiver second pulse |
| CN113038589B (en) * | 2021-03-04 | 2022-07-22 | 重庆邮电大学 | Matrix model estimation time synchronization method based on wireless network clustering topology |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1770667A2 (en) * | 2005-09-30 | 2007-04-04 | Robert Bosch GmbH | Method for synchronizing devices in wireless networks |
| WO2008147768A1 (en) * | 2007-05-25 | 2008-12-04 | New Jersey Institute Of Technology | Pulse-coupled discrete-time phase locked loops for wireless networks |
| CN101821978A (en) * | 2007-08-03 | 2010-09-01 | 康奈尔大学 | Pulse coupled oscillator synchronization for wireless communications |
-
2011
- 2011-01-07 CN CN201110002614XA patent/CN102045833B/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1770667A2 (en) * | 2005-09-30 | 2007-04-04 | Robert Bosch GmbH | Method for synchronizing devices in wireless networks |
| WO2008147768A1 (en) * | 2007-05-25 | 2008-12-04 | New Jersey Institute Of Technology | Pulse-coupled discrete-time phase locked loops for wireless networks |
| CN101821978A (en) * | 2007-08-03 | 2010-09-01 | 康奈尔大学 | Pulse coupled oscillator synchronization for wireless communications |
Non-Patent Citations (2)
| Title |
|---|
| 基于超宽带无线传感网络的导频优化脉冲同步算法;崔琪楣,陶小峰;《传感技术学报》;20090131;第22卷(第1期);100-106 * |
| 崔琪楣,陶小峰.基于超宽带无线传感网络的导频优化脉冲同步算法.《传感技术学报》.2009,第22卷(第1期),100-106. |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102045833A (en) | 2011-05-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8073465B2 (en) | Reciever, frequency deviation measuring unit and positioning and ranging system | |
| CN100483963C (en) | Orthogonal lower mixing frequency digital template matching pulse ultra wide band radio signal receiving method | |
| CN102045833B (en) | Communication synchronization method among wireless transceivers in wireless sensor network (WSN) | |
| CN102227891A (en) | Method for setting operation of routing node of asynchronous wireless communication network, network node and communication network implementing method | |
| US20050281320A1 (en) | Low power wireless communication system and protocol | |
| CN102027681A (en) | Method of and apparatus for synchronisation | |
| CN103945525A (en) | Hierarchical structure based wireless sensor network time synchronization method | |
| CN102326443B (en) | Systems and methods for PCO based UWB impulse radio with localized synchronization detection and retention | |
| CN109412691A (en) | A kind of optical fiber bidirectional time-frequency synchronization method and system that second pulse signal is taming | |
| CN105306095A (en) | Method and system for rapidly capturing relay satellite measurement and control system signal | |
| CN105187348A (en) | Any-rate CPFSK (Continuous Phase Frequency Shift Key) signal timing synchronization method | |
| US20140064422A1 (en) | Cdr circuit and terminal | |
| CN105306190A (en) | Closed loop type phase synchronization method based on accumulated positive feedback, and distributed communication system | |
| CN103002562A (en) | Hardware synchronizing method and system of wireless sensing network | |
| CN109120367B (en) | Time synchronization method based on troposphere scattering channel | |
| US20100197228A1 (en) | Clock synchronization method for a short range wireless communication network | |
| EP3503629B1 (en) | Transceiver device with real time clock | |
| CN101821978B (en) | Pulse coupled oscillator synchronization for wireless communications | |
| CN108809469A (en) | Time transfer receiver synchronized algorithm suitable for radar pulse communication equipment networking | |
| CN205336269U (en) | Frequency hopping transceiver on on -vehicle net platform | |
| CN104702350A (en) | Radio distance measuring system of aerial radio communication system | |
| CN105471470B (en) | Spread-spectrum signal frequency offset estimation methods based on decision-feedback | |
| CN101262287B (en) | Cluster pulse signal energy synchronization detection method in pulse ultra-broadband communication system | |
| CN106059699A (en) | Time synchronization method and system for wire1ess sensor network | |
| CN102523028A (en) | Method for transmitting local frequency reference source to far end |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20130515 Termination date: 20160107 |