CN106714316B - Method for distinguishing services based on network coding cooperation system in wireless sensor network - Google Patents
Method for distinguishing services based on network coding cooperation system in wireless sensor network Download PDFInfo
- Publication number
- CN106714316B CN106714316B CN201710116609.9A CN201710116609A CN106714316B CN 106714316 B CN106714316 B CN 106714316B CN 201710116609 A CN201710116609 A CN 201710116609A CN 106714316 B CN106714316 B CN 106714316B
- Authority
- CN
- China
- Prior art keywords
- node
- data
- reliability
- transmission
- network
- 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
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W72/00—Local resource management
- H04W72/04—Wireless resource allocation
- H04W72/044—Wireless resource allocation based on the type of the allocated resource
- H04W72/0473—Wireless resource allocation based on the type of the allocated resource the resource being transmission power
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W72/00—Local resource management
- H04W72/50—Allocation or scheduling criteria for wireless resources
- H04W72/54—Allocation or scheduling criteria for wireless resources based on quality criteria
-
- 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
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Quality & Reliability (AREA)
- Mobile Radio Communication Systems (AREA)
Abstract
The invention discloses a method for distinguishing services based on a network coding cooperation system in a wireless sensor network. The method considers that the transmitting power of each node is respectively set according to the reliability required by application, so that the transmitting power of the nodes is reduced to the minimum while the reliability is ensured, unnecessary energy consumption is saved, and the purpose of prolonging the service life of the network is achieved. The power of the node transmitting data is in positive correlation with the reliability of data transmission, and because a large amount of energy still exists in an area far away from the sink node when the network is dead, the residual energy is fully utilized, the data reliability can be better improved by improving the transmitting power of the node in the area, and the service life of the network cannot be influenced.
Description
Technical Field
The invention belongs to the field of wireless sensor networks, and particularly relates to a method for distinguishing services based on a network coding cooperation system in a wireless sensor network.
Background
The wireless sensor network consists of a large number of sensor nodes equipped with radio transceivers, which are scattered randomly in a working area and are responsible for sensing, monitoring and processing environmental data. In most cases, the wireless sensor network needs to operate for a long period of time without human intervention, and reliability and robustness are therefore essential requirements for wireless sensor network design. In the wireless communication process, interference caused by factors such as transmission environment and transmission medium can cause data to be affected to a certain extent when the data is transmitted in a wireless mode, so that the quality is reduced and even the data is lost. Therefore, realizing reliable communication transmission is one of the main problems to be solved in the field of wireless sensor networks. Furthermore, the energy-limited nature of the sensor nodes makes the energy conservation problem in wireless sensor networks another aspect that needs to be addressed urgently.
Currently, research on reliability is mainly focused on the following strategies: (1) a multipath routing protocol. The multipath routing protocol enables more nodes to be involved in the task of data transfer by establishing multiple paths between a sending node and a receiving node for data transmission. The data reliability is improved by selecting a plurality of better paths instead of a single best path. (2) An automatic repeat request technique. After the sending end sends the data packet to the receiving end, the response of the receiving end is needed, otherwise, the data packet needs to be sent again. (3) Forward error correction techniques. Forward error correction is an effective way to accomplish error correction of information using data encoding and decoding methods. The original data is encoded at the sending end according to a certain regularity, and the regularity enables the receiving end to automatically find and correct errors generated in transmission in a decoding mode after receiving the data packet. (4) Cooperative communication: cooperative communication is an effective method for improving system communication reliability and channel capacity by sharing antennas with each other by users in a certain manner to form virtual multiple channels and obtain space diversity gain in a multi-user network. (5) Network coding: unlike the traditional store-and-forward mode, network coding allows a relay node to encode, merge, and then forward information on multiple paths.
The implementation of the cooperative communication scheme enables the system communication reliability and the channel capacity to be improved to a certain extent. The cooperation system based on the network coding is further optimized in the aspect of saving transmission overhead, and the improvement of the network transmission efficiency is effectively ensured.
As part of the information infrastructure, wireless sensor networks need to serve different applications, each with different reliability requirements. The increase in reliability requirements represents an increase in energy consumption of the sensor nodes, which in turn will affect the overall lifetime of the network. Therefore, there is a need to develop a reliable and efficient method that can ensure reliability and achieve energy saving.
Disclosure of Invention
The invention provides a differentiated service method based on a network coding cooperation system in a wireless sensor network, which aims to determine the transmission power of nodes in the network according to the reliability requirement of application and minimize the energy consumption of the nodes on the premise of ensuring the reliability requirement of the application. And the nodes close to the base station need to bear more data forwarding tasks, so that the nodes are increased in energy consumption and more prone to death, the areas where the nodes are located are called hot areas, the areas where other nodes are located are called non-hot areas, after the transmission power of the nodes is determined, the transmission power of the nodes in the non-hot areas is improved, the reliability of data collection can be maximized on the premise that the service life of the network is not reduced, and the respective transmission power of all the nodes at the moment is calculated.
If the packet loss probability per hop is PPlrIf there are N nodes in each cluster, and there are only P surviving nodes, the probability that the receiving node can receive q packets from N packets is represented as P (P, q), and then it can be calculated as:
the data packet sent by each node is formed by combining the equally divided M data blocks, so that the original data block is recovered only by using the coding matrix with the rank of M. Suppose that a coding matrix of one order is randomly generated, let Pv,wIndicating the probability that the rank of the matrix is less than w. Node failure probability of PfIndicating that the reliability of the sink node receiving the packet is expressed as MFRlIt can be calculated by the following formula:
the reliability per hop, except for the aggregation node collecting the packets, is expressed as MFR0It can be calculated as:
if the requirement on the data reliability is MFR, and the data reliability needs to reach the MFR after the multi-hop transmission is finished, the relationship between the data transmission reliability of each hop and the final data reliability is as follows:
MFR＝1-(1-MFR0)hp-1·(1-MFRl)
where hp represents the total number of hops over which the data is transmitted.
Given the reliability requirement MFR of the application, the packet loss probability P per hop can be calculated from the above descriptionPlrAnd the value E of the transmission power needed by the node at the moment can be calculated by the following formulaA：
In the above formula, the first and second carbon atoms are,
mu is the ratio of the extreme value to the average value, and theta is the drain efficiency of the radio frequency power amplifier; n is a radical oflIs the influence of link interference or noise, NcIs the receiver noise figure; SNR0Represents a prescribed lower limit of the signal-to-noise ratio; d is the transmission distance, k is the path loss exponent; glRepresenting the transmission antenna gain, GrGain for the receive antenna; λ is the carrier wavelength; d0Is the reference distance of the transmitting node and the receiving node; sigma2Is a Rayleigh distribution scale parameter.
After the transmission power of the node is preliminarily determined to ensure the reliability of data, the transmission power of the non-hot-area node needs to be increased, and then a specific formula for calculating the transmission power of the node after the increase is as follows:
wherein i represents the service of the node for application i, x is the distance between the node and the base station, η is the transmission power lifting upper limit, PTIs the TX circuit power consumption, TbIs the transmission bit rate; thetatotIs the total number of packets sent by the node, OtotIs the total number of packets received by the node; erIs the energy consumption of the node receiving each bit of data;
is the number of packets the node receives from the previous hop node,
is the number of original data packets received,
is the number of state information collected by the node; r iscIs the cluster radius size, dxIs a node senderData transmission distance, k is path loss exponent; lt、ls、l0The length of the actually transmitted data packet, the length of the state information data packet and the length of the original data packet are respectively.
In conclusion, the differentiated services method adopted by the invention can transmit data with the lowest transmission power under the condition of the reliability required by the known application, the reliability requirement is ensured, the energy consumption of the hot-area nodes is reduced to the lowest, and the purpose of prolonging the service life of the network is achieved.
Drawings
FIG. 1 is a general block diagram of the process of the present invention;
FIG. 2 shows the transmission power E under the method of the present inventionAmpRelation to the failed transmission rate per hop MFR;
FIG. 3 is a diagram illustrating the situation of receiving and forwarding data amount by nodes at different distances from the base station under the condition of varying cluster node numbers;
FIG. 4 is a diagram illustrating a comparison of transmission power settings of nodes using the method of the present invention and nodes not employing the method;
FIG. 5 shows the transmission power settings of nodes at different locations after the method of the present invention for increasing the transmission power of nodes in a non-hot area;
FIG. 6 is a schematic diagram illustrating the comparison of transmission reliability between the method of the present invention and a conventional cooperative network coding method;
fig. 7 is a schematic diagram illustrating a comparison of network lifetime improvement when the method of the present invention and a cooperative network coding method are used for transmission.
Detailed Description
The invention will be further described with reference to examples and figures.
A method for differentiated services based on a network coding cooperation system in a wireless sensor network is disclosed, as shown in figure 1, different applications are subjected to data transmission by adopting different powers according to reliability requirements, and transmission power of nodes with surplus energy is improved within a certain range so as to increase data transmission reliability;
respectively selecting corresponding transmission power for applications with different reliability requirements to carry out data transmission;
the nodes close to the base station need to bear more data forwarding tasks, so that energy consumption is increased, and death is easy to occur.
In fig. 1, solid circles represent sensor nodes, and nodes within a dotted circle represent nodes within the same cluster, which are cooperative nodes with each other. The source nodes marked as solid are data generating nodes, and the base stations marked as solid are responsible for receiving data. The arrows in fig. 1 indicate the data transmission direction. Each sensor will send a data packet at a fixed time, so the life cycle of the network can be defined as a round. In each round of data transmission process, firstly, a source node broadcasts sensed data to other nodes in a cluster, and all the nodes in the cluster encode the data by using random network coding after receiving the data and then transmit the data to all the nodes in the next cluster. And after receiving the data, the nodes of the middle cluster recode the data and then continue to transmit the data to the next cluster. The above process is continuously executed, and the data transmission process of the round is stopped when the data packet is finally received by the node of the destination cluster. And finally, other nodes except the sink node in the target cluster send the data to the sink node, and finally, decoding all the received data. In each round of data transmission, if the same transmission power is always maintained, although reliability can be ensured, energy is wasted. Therefore, the differentiated service method can be used for transmitting data with the lowest transmission power under the condition of the reliability required by the known application, the reliability requirement is ensured, the energy consumption of the hot-zone nodes is reduced to the minimum, and the purpose of prolonging the service life of the network is achieved. Meanwhile, the transmission power of the non-hot area node is increased to the highest according to the difference value with the power increase upper limit, so that the data reliability is improved to the maximum, and the service life of the network cannot be influenced.
FIG. 2 shows the transmission power EAmpRelation to the failed transmission rate per hop MFR. As can be seen from fig. 2: as the transmission power increases, the data failure transmission rate decreases, i.e., the data reliability is improved. In particular, when the number of cluster nodes is 3, if the transmission power is increased from 0.005J to 0.095J, the MFR is decreased from 0.0245075 to 1.5946E-4, which means that increasing the transmission power by 19 times reduces the MFR by 154 times. Therefore, the data transmission failure rate can be effectively reduced by improving the transmission power, and the transmission reliability is improved.
Fig. 3 shows the situation that the nodes with different distances from the base station receive and forward data volume under the condition that the number of cluster nodes is changed. As can be seen in fig. 3: the change of the number of the cluster nodes does not affect the change of the number of the data transmitted by each node, and only affects the received data quantity. When the number of cluster nodes is increased gradually, the number of packets received by each node is increased, because each node needs to ensure that packets with the same number as the cluster nodes are received from the cluster of the previous hop in the cooperative communication system. Meanwhile, a common phenomenon can be observed, that is, data load born by nodes close to each other is far more than that of nodes in a non-hot area, so that more energy is consumed, and conversely, the data volume of nodes forwarded by nodes far away from each other is less and the energy consumption is less. Therefore, the mechanism for increasing the transmission power of the non-hot-zone nodes and maintaining the transmission power of the hot-zone nodes is effective.
The experimental setup of fig. 4 is: in a network with a network radius R of 400 m, 1000 nodes are deployed, and these nodes are responsible for transmitting data for a plurality of applications, and the applications have requirements on reliability, namely, MFR of 0.05, MFR of 0.1, MFR of 0.2, and MFR of 0.3. Fig. 4 shows the transmission power of the nodes at different distances from the base station when the reliability requirements of various applications are met under the condition that the number of cluster nodes N is 3, and the method is adoptedThe average transmitting power of the node under the method is invented. When all the node transmitting power meets the requirement that the information failure transmission rate is 0.05, the node transmitting power is maximum, and the transmitting power at the moment is Emax0.00614488. Comparing the method of the present invention with the plot with MFR of 0.05 shows that, when multiple applications are served, the result of weighting the energy consumption of each node using the method of the present invention is reduced to some extent, but the guarantee of data reliability is not affected, which is beneficial from the viewpoint of prolonging the network lifetime.
Fig. 5 shows the transmission power setting of nodes at different positions after the method for increasing the transmission power of the non-hot-zone nodes in the present invention is adopted. As can be seen by comparing with fig. 4, the power of the hot-zone nodes is not changed, but the energy of the rest nodes is improved to some extent, and the power is improved more and more the farther away, because the far zone retains more energy, and therefore more energy can be used to improve the transmission reliability. The data transmission reliability and the network energy utilization rate can be greatly improved by improving the energy of the non-hot-area nodes, but the power of the hot-area nodes is kept unchanged, and the service life of the network is ensured not to be influenced.
In the experimental scenario illustrated in fig. 6, in a network with a network radius R of 400 m, the number of fixed cluster nodes is 3, and the method of the present invention and the conventional cooperative network coding method are respectively adopted to transmit the application of the reliability requirement. As can be seen from fig. 6, although the node transmission reliability of the hot zone is not improved, the transmission power is improved for the nodes not in the hot zone, so that the transmission data failure rate MFR is greatly reduced. For end-to-end reliability of data, each node's guarantee of reliability determines the probability that the data will eventually be successfully received at the destination node. Therefore, the data reliability of the non-hotspot nodes is well guaranteed for the great reduction of the data failure transmission rate.
Fig. 7 shows that when the number of cluster nodes is 3 and the network radii are different, and the method of the present invention is used for transmitting applications with different reliability requirements respectively with the conventional cooperative network coding method, the method of the present invention can always maintain a better network lifetime than the cooperative network coding method. Further, the network life extension rate is calculated, and as can be seen from fig. 7, the method of the present invention improves the network life by about 18% on the premise of ensuring reliability. The experimental result shows that the method of the invention has obvious effect on prolonging the service life of the network under the same network condition.
In conclusion, the method of the invention can greatly improve the reliability of data transmission under the condition of the same network service life, and can also improve the service life of the network under the premise of ensuring the application reliability.
Claims (4)
1. A method for distinguishing services of a cooperative communication system based on network coding in a wireless sensor network is used for prolonging the service life of the network and increasing the reliability of data transmission, and is characterized in that: different applications adopt different powers to transmit data according to reliability requirements of the applications, and the transmission power of nodes with surplus energy is improved within a certain range so as to increase the reliability of data transmission;
respectively selecting corresponding transmission power for applications with different reliability requirements to carry out data transmission;
the nodes close to the base station need to bear more data forwarding tasks, so that energy consumption is increased, and death is easy to occur;
after the transmission power of the node is preliminarily determined to ensure the reliability of data, the transmission power of the non-hot-area node needs to be increased, and then a specific formula for calculating the transmission power of the node after the increase is as follows:
wherein i denotes that the node serves application i, and x denotes that the node is away from the base stationDistance η is the upper limit of transmission power boostTIs the TX circuit power consumption, TbIs the transmission bit rate; thetatotIs the total number of packets sent by the node, OtotIs the total number of packets received by the node; erIs the energy consumption of the node receiving each bit of data;
is the number of packets the node receives from the previous hop node,
is the number of original data packets received,
is the number of state information collected by the node; r iscIs the cluster radius size, dxIs the node sending data distance, k is the path loss exponent; lt、ls、l0The length of the actually transmitted data packet, the length of the state information data packet and the length of the original data packet are respectively.
2. The method of claim 1, wherein if the requirement for data reliability is MFR and the data reliability needs to reach MFR after the multi-hop transmission is finished, the relationship between the reliability of data transmission per hop and the final data reliability is as follows:
MFR＝1-(1-MFR0)hp-1·(1-MFRl)
wherein the reliability of the sink node receiving the data packet is expressed as MFRlThe reliability per hop, except for the aggregation node collecting the packets, is expressed as MFR0And hp represents the total number of hops traversed by the data transmission.
3. A method according to claim 1 or 2, characterized in that if the per-hop packet loss probability is required to be PPlrThen value E of node transmission powerACan be calculated by the following formula:
in the above formula, the first and second carbon atoms are,
mu is the ratio of the extreme value to the average value, and theta is the drain efficiency of the radio frequency power amplifier; n is a radical oflIs the influence of link interference or noise, NcIs the receiver noise figure; SNR0Represents a prescribed lower limit of the signal-to-noise ratio; d is the transmission distance, k is the path loss exponent; glRepresenting the transmission antenna gain, GrGain for the receive antenna; λ is the carrier wavelength; d0Is the reference distance of the transmitting node and the receiving node; sigma2Is a Rayleigh distribution scale parameter, N0Is the noise figure of the transmission node.
4. The method of claim 1, wherein the transmission power of all nodes is raised to the highest level according to the difference from the power raising upper limit η, which results in the maximum improvement of data reliability, and the upper limit η is set to ensure that the node energy consumption does not exceed the node with the maximum energy consumption, thereby ensuring that the network lifetime is not reduced.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710116609.9A CN106714316B (en) | 2017-03-01 | 2017-03-01 | Method for distinguishing services based on network coding cooperation system in wireless sensor network |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710116609.9A CN106714316B (en) | 2017-03-01 | 2017-03-01 | Method for distinguishing services based on network coding cooperation system in wireless sensor network |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106714316A CN106714316A (en) | 2017-05-24 |
| CN106714316B true CN106714316B (en) | 2020-05-01 |
Family
ID=58917834
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710116609.9A Expired - Fee Related CN106714316B (en) | 2017-03-01 | 2017-03-01 | Method for distinguishing services based on network coding cooperation system in wireless sensor network |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106714316B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108809455B (en) * | 2018-06-08 | 2021-01-08 | 广西大学 | RFEH-CR data transmission time distribution method based on network coding |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102761950A (en) * | 2011-04-28 | 2012-10-31 | 上海无线通信研究中心 | Self-adaption self-optimizing QoS (quality of service) transmission method for heterogeneous network |
| CN104486043A (en) * | 2014-12-29 | 2015-04-01 | 中山大学 | Self-adaptive cooperative network coding method for differentiated services |
| CN105451294A (en) * | 2015-11-04 | 2016-03-30 | 吴豪 | Method and apparatus for topological control of wireless sensor network |
| CN105680917A (en) * | 2016-02-25 | 2016-06-15 | 湖南师范大学附属中学 | Data transmission method for adaptively controlling transmission power in cooperative communication |
| CN106162793A (en) * | 2016-06-12 | 2016-11-23 | 中南大学 | A kind of wireless sensor network data transmission method using unequal network code level of redundancy |
-
2017
- 2017-03-01 CN CN201710116609.9A patent/CN106714316B/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102761950A (en) * | 2011-04-28 | 2012-10-31 | 上海无线通信研究中心 | Self-adaption self-optimizing QoS (quality of service) transmission method for heterogeneous network |
| CN104486043A (en) * | 2014-12-29 | 2015-04-01 | 中山大学 | Self-adaptive cooperative network coding method for differentiated services |
| CN105451294A (en) * | 2015-11-04 | 2016-03-30 | 吴豪 | Method and apparatus for topological control of wireless sensor network |
| CN105680917A (en) * | 2016-02-25 | 2016-06-15 | 湖南师范大学附属中学 | Data transmission method for adaptively controlling transmission power in cooperative communication |
| CN106162793A (en) * | 2016-06-12 | 2016-11-23 | 中南大学 | A kind of wireless sensor network data transmission method using unequal network code level of redundancy |
Also Published As
| Publication number | Publication date |
|---|---|
| CN106714316A (en) | 2017-05-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Hu et al. | Range extension without capacity penalty in cellular networks with digital fixed relays | |
| Adam et al. | Adaptive relay selection in cooperative wireless networks | |
| CN103997740B (en) | Cognitive-Cooperation network association resource allocation methods based on optimization utility | |
| CN101291169B (en) | Selection method of wireless relay station | |
| CN102868598A (en) | Control device and control method | |
| CN105357731A (en) | Energy-efficient wireless sensor network (WSN) routing protocol design method for use in electromagnetic interference environment | |
| Lakshmanan et al. | Diversity routing for multi-hop wireless networks with cooperative transmissions | |
| Chen et al. | A power efficiency routing and maintenance protocol in wireless multi-hop networks | |
| CN110149672B (en) | Improved I-LEACH route communication method | |
| Belabed et al. | An optimized weight-based clustering algorithm in wireless sensor networks | |
| US7583620B2 (en) | Link adaptation method using feedback information for wireless communication system | |
| CN102196587B (en) | Wireless-resource-dispatching method during multi-cell cooperation in relay-aided communication system | |
| Bhat et al. | Lifetime ratio improvement in relay nodes using CWSN for cooperative wireless sensor networks | |
| CN102547906A (en) | Wireless sensor network node cooperation method based on virtual MIMO (multi-input multi-output) | |
| CN106714316B (en) | Method for distinguishing services based on network coding cooperation system in wireless sensor network | |
| CN106912059B (en) | Cognitive relay network joint relay selection and resource allocation method supporting mutual information accumulation | |
| CN101562882A (en) | Method and device for allocating power | |
| CN109951239B (en) | Adaptive modulation method of energy collection relay system based on Bayesian classifier | |
| Djidi et al. | Adaptive relaying for wireless sensor networks leveraging wake-up receiver | |
| Jamil et al. | COPE: cooperative power and energy-efficient routing protocol for wireless sensor networks | |
| Wei et al. | A low-overhead energy-efficient ARQ protocol for wireless sensor networks | |
| CN115052324A (en) | Adaptive modulation method based on k-means clustering algorithm | |
| Cheikh et al. | Energy efficient relay selection method for clustered wireless sensor network | |
| Jiao et al. | Centralized scheduling tree construction under multi-channel ieee 802.16 mesh networks | |
| Ghanem et al. | A novel model for implicit cooperation between primary users and secondary users in cognitive radio‐cooperative communication systems |
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 | ||
| 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: 20200501 |