|
US$629.00 · In stock
Delivery: <= 6 days. True-PDF full-copy in English will be manually translated and delivered via email.
GB/T 38618-2020: Information technology - Telecommunications and information exchange between systems - Specification for high reliability and low latency wireless network communication protocol
Status: Valid
| Standard ID | Contents [version] | USD | STEP2 | [PDF] delivered in | Standard Title (Description) | Status | PDF |
| GB/T 38618-2020 | English | 629 |
Add to Cart
|
6 days [Need to translate]
|
Information technology - Telecommunications and information exchange between systems - Specification for high reliability and low latency wireless network communication protocol
| Valid |
GB/T 38618-2020
|
PDF similar to GB/T 38618-2020
Basic data | Standard ID | GB/T 38618-2020 (GB/T38618-2020) | | Description (Translated English) | Information technology - Telecommunications and information exchange between systems - Specification for high reliability and low latency wireless network communication protocol | | Sector / Industry | National Standard (Recommended) | | Classification of Chinese Standard | L79 | | Classification of International Standard | 35.110 | | Word Count Estimation | 34,343 | | Date of Issue | 2020-04-28 | | Date of Implementation | 2020-11-01 | | Quoted Standard | GB 15629.11-2003; GB/T 15629.15-2010; GB/T 26790.1-2011; IEEE 802.15.4-2011 | | Issuing agency(ies) | State Administration for Market Regulation, China National Standardization Administration | | Summary | This standard specifies the operating frequency range, radio frequency requirements and services of the physical layer of wireless communication networks in high-reliability and low-latency application scenarios, as well as the data link layer reference architecture, MAC layer functions, precise time synchronization, and data link sublayer functions. And adaptive channel hopping and deterministic scheduling. This standard applies to the planning, deployment and implementation of wireless networks in industrial field applications. | GB/T 38618-2020: Information technology - Telecommunications and information exchange between systems - Specification for high reliability and low latency wireless network communication protocol
---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order.
Information technology - Telecommunications and information exchange between systems - Specification for high reliability and low latency wireless network communication protocol
ICS 35.110
L79
National Standards of People's Republic of China
Telecommunication and information exchange between information technology systems
High-reliability and low-latency wireless network communication protocol specification
2020-04-28 released
2020-11-01 implementation
State Administration for Market Regulation
Issued by the National Standardization Management Committee
Table of contents
Foreword Ⅰ
1 Scope 1
2 Normative references 1
3 Terms and definitions 1
4 Abbreviations 3
5 Overview 4
6 Physical layer 5
6.1 Overview 5
6.2 Operating frequency range 5
6.3 Physical layer RF requirements 6
6.4 Physical layer service specification 8
7 Data link layer 21
7.1 Data link layer reference model 21
7.2 MAC layer 22
7.3 Data link sublayer 25
Reference 30
Telecommunication and information exchange between information technology systems
High-reliability and low-latency wireless network communication protocol specification
1 Scope
This standard specifies the operating frequency range, radio frequency requirements and services of the physical layer of wireless communication networks in high-reliability and low-latency application scenarios.
And data link layer reference architecture, MAC layer functions, precise time synchronization, data link sublayer functions, and adaptive channel hopping and determinism
Scheduling etc.
This standard applies to the planning, deployment and implementation of wireless networks in industrial-level field applications.
2 Normative references
The following documents are indispensable for the application of this document. For dated reference documents, only the dated version applies to this article
Pieces. For undated references, the latest version (including all amendments) applies to this document.
GB 15629.11-2003 Information technology system telecommunications and information exchange between local area network and metropolitan area network specific requirements
Part 11.Wireless LAN media access control and physical layer specification
GB/T 15629.15-2010 Information technology system telecommunications and information exchange specific requirements for local area networks and metropolitan area networks
Part 15.Low-speed wireless personal area network (WPAN) media access control and physical layer specification
GB/T 26790.1-2011 Industrial Wireless Network WIA Specification Part 1.WIA System Structure and Communication Specification for Process Automation
IEEE802.15.4-2011 Local Area Network and Metropolitan Area Network Part 15.4.Low Rate Wireless Personal Area Network
3 Terms and definitions
The following terms and definitions defined in GB/T 26790.1-2011 apply to this document. For ease of use, the following is repeated
Some terms and definitions in GB/T 26790.1-2011.
3.1
Adaptive frequency hopping
In each time slot of the communication phase in the industrial wireless network superframe cluster, the communication channel is changed according to the actual channel conditions.
[GB/T 26790.1-2011, definition 3.1.3]
3.2
Adaptive frequency switching
In the industrial wireless network superframe, the beacon phase and the active period replace the communication channel according to the actual channel condition within a superframe period.
Different channels are used in different super frame periods.
[GB/T 26790.1-2011, definition 3.1.4]
3.3
Beacon
In industrial wireless networks, the access point or the terminal node device that acts as the parent node broadcasts the frame of the node.
Note. The beacon frame is used for a new parent node or terminal node to join the industrial wireless network.
3.4
broadcast
Send the packet to all the nodes that can be received in the industrial wireless network.
[GB/T 26790.1-2011, definition 3.1.8]
3.5
channel
The radio frequency medium used to transfer packets from the sender to the receiver.
3.6
A logical node group including a parent node and multiple terminal nodes.
3.7
coexist
A network has the ability to perform tasks without being disturbed or disturbing other networks in the same environment.
Note. These networks follow the same or different rules.
3.8
compatible
A network can provide services to or receive services from other networks, and realize multiple networks through service exchange
The ability to operate effectively between.
3.9
Data link sublayer
Located above the MAC layer, it is used to process industrial wireless network topology, link and communication resources.
[GB/T 26790.1-2011, definition 3.1.17]
3.10
Terminal node
Equipment installed in the industrial site to connect or control the production process.
3.11
Frequency hopping
Transceiving channel switching method, the purpose is to resist interference and reduce signal fading.
[GB/T 26790.1-2011, definition 3.1.20]
3.12
Access Point
Devices that connect industrial wireless networks with other factory networks.
3.13
Hop
In industrial wireless networks, the process of packet transmission between two adjacent nodes without the participation of other nodes.
Note. Multi-hop is used to extend the transmission distance, bypass interference sources and avoid blocking.
3.14
Interoperability
The ability of two or more networks to exchange information with each other and to utilize the exchanged information.
3.15
Join
Industrial wireless network nodes are authenticated and allowed to access the industrial wireless network.
6.3.1.5 Receiver ED
The test scenario of the receiving end ED of the 433MHz~510MHz frequency band module should conform to the stronger one based on GB 15629.11-2003
Interference scenario, that is, there are at least two commercial wireless networks, and they are continuously connected with two commercial wireless networks for data exchange.
In this scenario, the ED curve of each channel in the 433MHz frequency band meets the accuracy requirements of 6dB2), and it is linear in this range.
And moderately monotonous.
6.3.2 RF requirements for 470MHz~510MHz frequency band
6.3.2.1 Modulation method
The receiving end of the 470MHz~510MHz frequency band module uses GFSK modulation, and the data rate is 100kbit/s.
6.3.2.2 Receiver sensitivity
The sensitivity of the module receiver in the 470MHz~510MHz frequency band should meet. in each channel of the 470MHz~510MHz frequency band,
When the receiver sensitivity drops to -107dBm1), the packet error rate is not more than 1%.
6.3.2.3 Interference suppression at the receiving end (adjacent channel)
The interference suppression (adjacent channel) at the receiving end of the 470MHz~510 MHz frequency band module should meet. when the interference signal power rises to
-50dBm1), the packet error rate is not more than 1%.
The specific condition is that the input power in the working channel is equal to -82dBm1), and the input power of the interference signal of the interval channel to the working channel is equal to
The value is at least 0dB2).
6.3.2.4 Interference suppression at the receiving end (non-adjacent channels)
470MHz~510MHz frequency band module receiving end interference suppression (non-adjacent channel) should meet. when the interference signal power rises to
-35dBm1), the packet error rate is not more than 1%.
The specific condition is that the input power in the working channel is equal to 82dBm1), and the input power of the interference signal of the non-adjacent channel to the working channel is the same.
The value is at least 30dB2).
6.3.2.5 Receiver ED
The test scenario of the receiving end ED of the 470MHz~510MHz module should meet the strong interference based on GB 15629.11-2003
The scenario is that there are at least two commercial wireless networks, and they are continuously connected to two commercial wireless networks for data exchange. here
In the scene, the ED curve of each channel in the 470MHz~510MHz frequency band meets the accuracy requirements of 6dB2), within this range.
It is linear and moderately monotonous.
6.3.3 780MHz frequency band RF requirements
6.3.3.1 Modulation method
The receiving end of the 780MHz frequency band module uses O-QPSK modulation, and the data rate is 250kbit/s.
6.3.3.2 Receiver sensitivity
The receiver sensitivity of the 780MHz frequency band module should comply with. In each channel of the 780MHz frequency band, the receiver sensitivity is reduced
-100dBm1), the packet error rate is not more than 1%.
6.3.3.3 Interference suppression at the receiving end (adjacent channel)
The interference suppression (adjacent channel) at the receiving end of the 780MHz frequency band module should meet. when the interference signal power rises to -40dBm1), the packet error
The rate is not more than 1%.
The specific condition is that the input power in the working channel is equal to -82dBm1), and the input power of the interference signal of the interval channel to the working channel is equal to
The value is at least 0dB2).
6.3.3.4 Interference suppression at the receiving end (non-adjacent channels)
The interference suppression (non-adjacent channel) at the receiving end of the 780MHz frequency band module should meet. when the interference signal power rises to -25dBm1), the error
The package rate is not more than 1%.
The specific condition is that the input power in the working channel is equal to -82dBm1), the input power of the interference signal of the non-adjacent channel to the working channel
The relative value is at least 30dB2).
6.3.3.5 Receiver ED
The test scenario of the receiving end ED of the 780MHz frequency band module should meet the strong interference scenario based on GB 15629.11-2003.
That is, there are at least two commercial wireless networks, and they are continuously connected to two commercial wireless networks for data exchange. In this scenario
The ED curve of each channel of the 780MHz module satisfies the accuracy requirement of 6dB2), which is linear and moderately monotonous in this range.
6.3.4 Coexistence of Same Frequency Commercial Wireless Network
6.3.4.1 Definition of Coexistence
The coexistence of co-frequency commercial wireless networks is defined as high-reliability and low-latency wireless networks that work in the 2.4GISM frequency band.
The frequency band is based on the channel interference of the GB 15629.11-2003 wireless network to achieve coexistence with the GB 15629.11-2003 wireless network.
The coexistence test is mainly carried out under three different levels of wireless network interference scenarios based on GB 15629.11-2003.
6.3.4.2 Interference scenario
3 wireless network interference scenarios based on GB 15629.11-2003.
a) Interference scenario 1--light interference scenario. In this interference scenario, there is a commercial GB 15629.11-2003 wireless network, and
The commercial wireless network has not made a deliberate network connection, that is, has not constructed deliberate data interaction interference;
b) Interference Scenario 2-General Interference Scenario. In this interference scenario, there are at least 2 commercial GB 15629.11-2003 wireless networks
Network, and make a deliberate intermittent network connection with one of the commercial GB 15629.11-2003 wireless networks, that is, a small amount of
Data interaction without continuous interference;
c) Interference scenario 3-Strong interference scenario. In this interference scenario, there are at least 2 commercial GB 15629.11-2003 wireless networks
Network, and with two commercial GB 15629.11-2003 wireless networks for purposeful continuous network connection, that is, continuous data interaction.
6.3.4.3 Co-existence determination of co-frequency commercial wireless networks
The coexistence of the 2.4GHz module and the same-frequency commercial wireless network shall comply with the wireless network interference scenario 1 in GB 15629.11-2003 respectively.
In the line network interference scenario 2, the wireless network interference scenario 3, the 2.4GHz module can automatically jump to the 2.4GHz frequency band and is not affected by the current wireless network.
It can communicate with the channel interfered by the working channel of the network to realize coexistence with the GB 15629.11-2003 wireless network.
6.4 Physical layer service specification
6.4.1 Physical layer reference model
The reference model of the physical layer (PHY) service is shown in Figure 2.
The physical layer defines two services. PHY data service connected to the physical layer data service access point (PDSAP) and connected to the physical layer
Layer management entity service access point (PLMESAP) PHY management service. The physical layer management entity (PLME) maintains a
Identify the MAC command being used. The payload field of the command frame contains the MAC command itself. The payload field of the command frame has a variable length, and
And it contains specific and different data from the command frame type.
7.2.2 Accurate time synchronization
7.2.2.1 Classification
The key technology of time synchronization is mainly divided into the advertising frame/beacon frame time synchronization method and the command frame time synchronization method.
7.2.2.2 Beacon frame time synchronization
The beacon frame time synchronization is one-way time synchronization based on broadcasting. In order to reduce the energy overhead caused by time synchronization, the IEEE
In the 802.15.4-2011 physical layer industrial wireless network, beacon frames can be used to complete time synchronization. Beacon frame time synchronization steps
as follows.
a) The access point periodically broadcasts time synchronization beacon frames to its neighbor parent nodes, and loads the beacon transmission time into the beacon frame
Designated fields;
b) The parent node generates an SFD interrupt when receiving a beacon frame and records the local beacon reception time;
c) The parent node calculates the time deviation between the clock of the node and the standard clock through the timestamps obtained by sending and receiving, and compensates for the local clock,
In this way, synchronization with the time source node is realized.
Similarly, in the star network, the parent node periodically broadcasts beacon frames, and the terminal nodes in the star network also receive beacon frames to complete synchronization.
In this way, all nodes in the network can synchronize with their own time sources, and finally complete the time synchronization of the entire network.
7.2.2.3 Command frame time synchronization
In order to meet the accuracy requirements of different industrial applications, the accuracy of time synchronization can reach milliseconds (ms) or even tens of microseconds (μs).
Reliable low-latency wireless networks can also use dedicated time synchronization command frames for secondary synchronization.
The time synchronization command frame can be sent periodically by the access point and the terminal node acting as the parent node.
--- The access point uses the inter-cluster communication period to send time synchronization command frames to achieve time synchronization of the mesh network;
--- The parent node uses the intra-cluster communication period to send time synchronization command frames to achieve time synchronization in the star network.
In the specific design of the time synchronization command frame, the following two command frame synchronization methods should be adopted.
a) Periodic broadcast synchronization. The time source node periodically sends time synchronization command frames, which is similar to beacon frame synchronization.
b) Point-to-point synchronization on demand. The node applies for the time synchronization command frame from the time source. The steps are as follows.
1) The node sends a synchronization request to load and send the time stamp T1 to the time source node;
2) The time source node receives the request, records the received request time T2, and parses the time information in the request;
3) The time source node sends a time synchronization command frame to the node at T3, and the synchronization node needs to receive the command frame at T4;
The node that needs to be synchronized calculates the time deviation θ value and the synchronization frame transmission time d by equations (1) and (2).
θ=
(T1-T2)-(T4-T3)
(1)
d=
(T2-T1) (T4-T3)
(2)
In formula (1) and formula (2).
θ --- time deviation;
d ---Synchronous frame transmission time;
T1 --- node sending time;
T2 --- the time when the source node receives the request;
T3 ---Synchronization command frame sending time;
T4 ---Command frame receiving time.
4) The application synchronization node compensates its local clock according to the calculated time deviation.
7.2.2.4 Multi-hop network time synchronization compensation
7.2.2.4.1 Synchronous compensation
In large-scale thousands-point wireless network applications with high reliability and low latency, data messages sent by terminal nodes often need to be transmitted through multiple hops
Only the input can reach the access point, and the time synchronization accuracy error will accumulate as the number of hops increases. Multi-hop network time synchronization should be synchronized
Step compensation.
7.2.2.4.2 Fitting frequency drift
In addition to the initial time deviation of the two device clocks, the source of time synchronization error is the crystal drift of the clock is the most important factor.
The algorithm that uses multiple synchronizations to do linear fitting to the clock's crystal frequency drift can compensate for the drift value. When the algorithm has established a function
The clock synchronization model is shown in equation (3).
Tn=αTm β (3)
Where.
Tn --- Receiving time of synchronization frame;
α --- Crystal frequency drift;
Tm --- send time;
β --- Original time deviation.
Periodic synchronization can get multiple time data points, and the parameter fitting of these points can get the frequency drift and time deviation value.
7.2.2.4.3 Statistical parameter estimation
Another important source of time synchronization error is the time delay in the sending, transmission and reception of synchronization messages, including
Deterministic delay and uncertainty delay. In order to reduce the time delay error, the statistical signal processing method is used to estimate the time deviation.
The clock synchronization model is shown in equation (4).
TSA2i =fskew×(TS1i XSAi dSA) θSAoffset (4)
Where.
TSA2i ---The synchronization message reception time of node A for the i-th synchronization;
TS1i --- Time source node S synchronization message sending time;
fskew---the relative frequency drift of the two nodes;
θSAoffset---the original time deviation of the two nodes;
dSA --- message transmission time (deterministic delay);
XSAi --- Random delay during message transmission (uncertainty delay).
Assuming that XSAi obeys the Gaussian normal distribution, the maximum likelihood estimation can be used to estimate the time deviation to obtain the time deviation.
Shift value.
7.2.2.4.4 Monitor synchronization
Monitor synchronization is used to reduce the accumulation of multi-hop network synchronization errors. This method uses the "monitoring" effect produced by the broadcasting characteristics of the wireless channel
As a result, the node at the next hop can monitor the synchronization process between the node of the current layer and the node of the previous hop within the broadcast range to achieve the goal of synchronization.
of. In this way, it can effectively control and reduce the number of hops in the transmission of synchronization messages and reduce the accumulation of errors.
7.3 Data link sublayer
7.3.1 Data link sublayer functions
7.3.1.1 Function overview
The DLSL for high-reliability and low-latency wireless networks provides service interfaces for the network layer and the MAC layer. DLSL includes the number of data link sublayers
Data Entity (DLDE) and Data Link Sublayer Management Entity (DLME). DLDE is responsible for providing data service interface, DLME is used for configuration
DLSL parameters and monitoring the operation of DLSL.
7.3.1.2 Coexistence
High-reliability and low-latency wireless networks need to consider the coexistence of other industrial-grade wireless networks, and ensure that the network will not be
Operational interference problems due to other external factors. After the coexistence problem is solved, the interconnection problem of the network can be considered. That is different from
Wireless network connection improves the interoperability of industrial applications.
7.3.1.3 Time slot communication
The key to time slot communication is that the transmission of the frame must be completed within a limited time, that is, the frame must be transmitted in the specified time slot and cannot be delayed.
late. The time slot length of the data link sublayer in the high-reliability and low-latency wireless network is maintained with the time slot length of the IEEE802.15.4-2011 protocol
compatible.
The high-reliability and low-latency wireless network supports variable-length time slots. The length of the time slot is set by the network manager after the node joins the network.
7.3.1.4 Superframe
High-reliability and low-latency wireless networks can selectively use superframe structures, and there can be multiple superframes, and each superframe is in the adjacent working range
There are different channel hopping sequences inside, and there are multiple time slots, each of which can be configured as a corresponding link. Super frame format by network
Manager definition. Super frames can be divided into two types. management super frames and data super frames.
a) The management superframe is generally used to complete the management of nodes;
b) Data superframes are generally used to configure communications related to user application processes.
The super frame is defined by the network beacon and sent by the terminal node acting as the parent node. The first time slot is the PAN beacon frame. Beacon frame
Transmission is performed in the first time slot of each superframe. If the master node does not use the superframe structure, then it will turn off the beacon transmission. letter
The mark is mainly used to synchronize each slave node with the master coordinator, identify the PAN, and describe the structure of the superframe. If any slave node wants to be in two
To communicate during the contention access period (CAP) between beacons, it is necessary to use multiple access with time slot and conflicting carrier detection (CSMA/
The CA) mechanism competes and communicates with other nodes, and only the node that has obtained the channel access permission in the current time slot can transmit in the time slot.
Send or receive frames. All transactions that need to be processed will be processed before the next network beacon slot. During the competition-free period (CFP), data
The transmission does not use the CSMA/CA mechanism. As long as the device is allocated a GTS, the device can directly perform data in the GTS containing time slot
Transmission.
In order to reduce the power consumption of nodes, the superframe is divided into two parts, namely the active part and the static part. In the static part, the master coordinator and
PAN nodes do not have any contact, enter a low-power mode, in order to achieve the purpose of reducing node power consumption.
7.3.1.5 Link
The link contains time and frequency, and determines how the node will occupy the time slot for data transmission. The type of link includes sending link, receiving link
And share the transmission link. Among them, in the shared transmission link, nodes can simultaneously compete to use the link to send data. And in the sending link and receiving
The receiving link can only allow the designated node to use the link to send and receive data.
7.3.2 Adaptive channel hopping
7.3.2.1 Overview of adaptive channel hopping function
In high-reliability and low-delay wireless networks, network nodes should support adaptive channel hopping.
Adaptive channel hopping technology is a major anti-interference technology in short-range wireless communication networks. High reliability and low latency wireless network channel
The sequence can be pre-designated by the network manager, and 3 channel hopping methods can be used. User-specified parameters such as channel hopping sequence and interval time
After that, the hardware can directly complete the frequency management, and jump to the designated channel w...
Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of GB/T 38618-2020_English be delivered?Answer: Upon your order, we will start to translate GB/T 38618-2020_English as soon as possible, and keep you informed of the progress. The lead time is typically 4 ~ 6 working days. The lengthier the document the longer the lead time. Question 2: Can I share the purchased PDF of GB/T 38618-2020_English with my colleagues?Answer: Yes. The purchased PDF of GB/T 38618-2020_English will be deemed to be sold to your employer/organization who actually pays for it, including your colleagues and your employer's intranet. Question 3: Does the price include tax/VAT?Answer: Yes. Our tax invoice, downloaded/delivered in 9 seconds, includes all tax/VAT and complies with 100+ countries' tax regulations (tax exempted in 100+ countries) -- See Avoidance of Double Taxation Agreements (DTAs): List of DTAs signed between Singapore and 100+ countriesQuestion 4: Do you accept my currency other than USD?Answer: Yes. If you need your currency to be printed on the invoice, please write an email to [email protected]. In 2 working-hours, we will create a special link for you to pay in any currencies. Otherwise, follow the normal steps: Add to Cart -- Checkout -- Select your currency to pay.
|