GB/T 39723-2020Technical specification for communication network system of BeiDou ground-based augmentation system (English PDF)

3.1 Terms and definitions

The terms and definitions defined in GB/T 39267-2020 and GB/T 32402 apply to this document.

3.2 Abbreviations

The following abbreviations apply to this document.

4.1 Overall architecture

The overall architecture of the communication network system is composed of three parts. data return network, data broadcast network and service access network. The communication network system

The architecture diagram is shown in Figure 1.

4.2 Data return network

It is composed of a two-way link communication network connecting the reference station and the monitoring station to the data processing center. The data backhaul network is mainly based on Beidou

The base station of the enhanced system transmits satellite observation data and operation and maintenance monitoring data, and receives enhanced data products for the monitoring station and transmits positioning data

And monitoring data to provide communication network.

4.3 Data Broadcasting Network

It is composed of one-way and two-way link communication network from the data processing center to the broadcasting system to the user. The data broadcast network is mainly for the North

The bucket ground-based augmentation system broadcasts satellite guidance to users through satellite, digital network (mobile communication network, Internet, etc.), digital broadcasting and other broadcasting methods.

Aviation enhanced data products to provide communication networks.

4.4 Service access network

It consists of a two-way link communication network from the data processing center to the backup system and the operation service platform. The service access network is mainly

Back up data to the backup system for the data processing center, support data recovery and use when needed, and provide data processing for the operation service platform

The communication network through which the heart or data processing center transmits operation service-related data to the operation service platform.

5.1 Network topology design

5.1.1

Network design should follow practicality, advancement, high reliability, standardization, openness, flexibility, scalability, ease of operation, and manageability

Principles of rationality and economy.

5.1.2

The communication network system adopts a two-layer or three-layer star network architecture design. For the topology relationship of the two-layer star network architecture of the communication network system, see

Figure 2.The topological relationship of the three-layer star network architecture of the communication network system is shown in Figure 3.

5.1.3

The two-layer star network architecture design is divided into the core layer and the base station access layer. The core layer is the data processing center and the access layer is the base layer.

Quasi station or monitoring station.

5.1.4

The three-layer star network architecture design is divided into core layer, convergence layer and access layer. The core layer is the data processing center and the convergence layer is the ground.

In the area convergence center, the access layer is the base station or monitoring station.

5.1.5

The core layer and convergence layer should adopt a dual-backup redundant architecture (including routers, etc.).

5.1.6

The access layer should adopt a router with security protection.

5.1.7

The core layer and the convergence layer should be connected by at least two independent mutual backup transmission links.

5.1.8

Below the convergence layer, the number of connected transmission links should be selected based on the actual situation.

Figure 3 Topological diagram of three-layer star network architecture of communication network system

5.2 Transmission link design

5.2.1

The link should use a reliable carrier's dedicated line or other securely encrypted lines.

5.2.2

The transmission link bandwidth from the access layer to the convergence layer or from the access layer to the core layer should be selected according to the actual data bandwidth requirements.

At 2Mbps.

5.2.3

The link type should select reliable SDH, MSTP dedicated lines, and links with corresponding data scale bandwidth.

5.2.4

The transmission link bandwidth from the core layer to the convergence layer should be selected according to the actual data bandwidth requirements, and should not be less than 10Mbps.

5.3 Route planning

5.3.1 Main route planning

5.3.1.1

A dynamic routing protocol shall be used within the core layer of the communication network system, from the core layer to the convergence layer.

5.3.1.2

Dynamic routing protocol or static routing protocol can be used within the convergence layer, from the core layer to the access layer, and from the convergence layer to the access layer.

5.3.1.3

OSPF or BGP protocol can be used within the core layer, from the core layer to the convergence layer.

5.3.1.4

OSPF or static routing protocols can be used within the convergence layer, from the core layer to the access layer, and from the convergence layer to the access layer.

5.3.2 Auxiliary routing line planning

The auxiliary route plan is designed with reference to the main route plan.

5.3.3 IP address planning

5.3.3.1

The planning and division of IP addresses should meet the requirements of the Beidou Foundation Enhancement System for IP addresses in the current project and the needs of future development.

If necessary, the corresponding address segment should be reserved for future business development.

5.3.3.2

CIDR technology should be used to reduce the size of the router routing table, speed up the convergence speed of router routing, and reduce broadcasts in the network.

The size of the routing information.

5.3.3.3

VLSM technology should be used in the allocation of IP addresses to ensure the efficiency of IP address utilization.

5.3.3.4

The address segments of various places shall be allocated according to the size of the business volume.

5.3.3.5

IP address allocation should try to allocate continuous IP address space to each base station; in each base station, the same business and

The function should try to allocate continuous IP address space.

5.4 Security and confidentiality

5.4.1

Communication network security should meet the requirements of GB/T 22239 for network security protection level 3 and above.

5.4.2

The security of the communication network system is divided into three parts. data security, link security and access security.

5.4.3

Data management shall comply with relevant national data security and confidentiality requirements. For mobile broadcast and RTK and applications involving two-way communication

Users must have measures to ensure the security and confidentiality of the data processing center.

5.4.4

Data transmission should be carried out using dedicated channel dedicated line of the operator, or other securely encrypted lines. Secure encryption

The algorithm is in accordance with relevant regulations.

5.4.5

For the network equipment used in the network system, the access rights should be strictly controlled, weak passwords should be avoided, and login accounts should be changed regularly information.

5.4.6

The data access in the network system should be controlled, access control strategies should be deployed, and invalid access rights to the base station should be closed.

6.1 Network transmission

6.1.1

The core layer and convergence layer network equipment should be able to support the operation of static routing, OSPF, BGP, and multicast protocols.

6.1.2

The access layer network equipment can support static routing and OSPF protocol.

6.1.3

The core layer, convergence layer, and access layer network equipment should have network transmission security functions.

6.2 Network configuration and monitoring

6.2.1

The network equipment should be able to be remotely logged in and configured.

6.2.2

The network system should be monitored and can automatically alert when an abnormality occurs.

6.3 Network transmission link

6.3.1

It has basic data packet transmission function, and does not filter general network protocols.

6.3.2

The bandwidth of the transmission link can be flexibly expanded as needed.

6.4 Network security and confidentiality

6.4.1

The transmission line should have the ability to support security services, and should be able to support channel exclusive or support encryption through security algorithms.

6.4.2

Network equipment should have security service functions, should be able to support access control strategies and strong password settings.

7.1 Network equipment performance

7.1.1 Core layer network equipment

The core network equipment should be a reliable high-end router or a three-layer switch, and the technical indicators should meet the following requirements.

a) The maximum throughput is not less than 273Gbps;

b) The packet forwarding rate is not less than 460Mpps;

c) The main control switch card, power supply, and interface module should be hot-swappable;

d) The main control switch card, switch network board, power supply, and fan of key components should support 11 redundant backup;

e) The reliability of the equipment is not less than 0.99999;

f) MTBF is not less than 10000h;

g) The forwarding delay is less than 1ms.

7.1.2 Convergence layer network equipment

The convergence layer network equipment should be a reliable mid-range router or a three-layer switch, and the technical indicators should meet the following requirements.

a) The maximum throughput is not less than 50Gbps;

b) The packet forwarding rate is not less than 100Mpps;

c) The reliability of the equipment is not less than 0.99999;

d) MTBF is not less than 10000h;

e) The forwarding delay is less than 1ms.

7.1.3 Access layer network equipment

The access layer network equipment should be a reliable router or firewall, and the technical indicators should meet the following requirements.

a) The maximum throughput is not less than 5Gbps;

b) The reliability of the equipment is not less than 0.99999;

c) MTBF is not less than 10000h;

d) The forwarding delay is less than 1ms.

7.2 Network bandwidth

The network bandwidth should meet the following requirements.

a) The access layer bandwidth is not less than 2Mbps;

b) The link bandwidth from the core layer to the convergence layer should be selected according to the actual data bandwidth requirements, at least 10Mbps.

7.3 Network delay

The network delay should meet the following requirements.

a) The total delay from the reference station to the data processing center should not be greater than 500ms;

b) The number of qualified lines with network delay should not be less than 95% of the total number.

7.4 Network availability

7.4.1

The availability rate of a single transmission link has an average packet loss rate of less than 1%.

7.4.2

The overall availability rate of the transmission link should be satisfied, the packet loss rate of a single line is less than 1%, and the proportion of a single line that is qualified by the system should not be small

At 95%.

7.4.3

The overall availability rate of the communication network system should not be less than 95%.

7.5 Cybersecurity and confidentiality

The communication network system should adopt corresponding encryption technology on the data and communication links to ensure that the data transmitted in the system conforms to the relevant

Security and confidentiality requirements.

10.1 Purpose of acceptance test

Test and verify the function, performance, and security of the built communication network to ensure the function, performance, and stability of network data transmission

And safety.

10.2 Timing of acceptance test

After the completion of the construction of the communication network system, the acceptance test shall be carried out after trial operation for at least one month.

10.3 Acceptance test items

The object of the acceptance test of the communication network system is the data return network, the data broadcast network and the service access network, and the acceptance test items and items

Purpose requirements chapter number and corresponding test method chapter number are shown in Table 1.

10.4 Testing and acceptance

10.4.1

The constructed communication network system can be tested and accepted after a specified period of trial operation.

10.4.2

The acceptance test shall be performed on the acceptance test items listed in Table 1 according to the test outline, test rules and the test methods in Chapter 11.

Network function, performance and security testing.

10.4.3

The test evaluation of the acceptance test items should use the corresponding test evaluation table in Chapter 12 for test evaluation and record the results.

10.4.4

When the test does not meet any of the indicators in Chapter 12, it is unqualified; the unqualified should be rectified until it is passed.

acceptance.

10.4.5

After passing the acceptance test, relevant documents should be delivered in accordance with Chapter 13.

10.4.6

Only when all acceptance test items pass the test and the relevant documents submitted meet the requirements, the acceptance can be determined.

11.1 Network transmission test method

Connect the test equipment, enable OSPF, BGP, static routing, and IPSec functions on the equipment at both ends, and confirm the operating status of the protocol.

If the line is successful, confirm that the corresponding protocol and security function are supported, otherwise this item will not pass. The network transmission function item mainly tests the network equipment for the network

Support status of network protocols and security functions.

11.2 Network configuration and monitoring test method

After logging in to the device remotely, configure basic functions through the page or command line to test whether it has the network configuration function.

Simulate the abnormal status of the relevant parameters of the network equipment, observe whether the monitoring error function works, and test whether it has the network monitoring function.

11.3 Network transmission link test method

Connect network devices that have passed the network function test at both ends of the link, and enable OSPF, BGP, static routing,

IPSec function, confirm the data transmission and protocol operation status, if the operation is successful, confirm that the transmission link opens the relevant network protocol port, pass function test.

11.4 Network equipment performance test method

Through the use of analog traffic input equivalent to the network operation capacity, the limit throughput and backplane bandwidth are measured, and the accelerated life test is tested.

At the same time, the nominal value in the manufacturer’s factory report is used for comparison and verification. When the difference between the test value and the standard value does not exceed ±15%, it is recognized

Passed for the test.

11.5 Network bandwidth test method

By simulating TCP or FTP traffic at both ends of the link, the limit bandwidth of the transmission link is measured, and the limit bandwidth is compared with the nominal bandwidth.

If the difference between the limited bandwidth and the nomin...