CN110191454B

CN110191454B - Method for realizing capacity expansion of number of access devices at Zigbee coordinator end

Info

Publication number: CN110191454B
Application number: CN201910630294.9A
Authority: CN
Inventors: 李晓冬; 周刚; 宋世成; 陈修强
Original assignee: Sichuan Changhong Electric Co Ltd
Current assignee: Sichuan Changhong Electric Co Ltd
Priority date: 2019-07-12
Filing date: 2019-07-12
Publication date: 2021-06-22
Anticipated expiration: 2039-07-12
Also published as: CN110191454A

Abstract

The invention discloses a method for realizing the capacity expansion of the number of access devices at a Zigbee coordinator end, which is realized based on Zigbee3.0 and comprises the following steps: A. changing the network access process of Zigbee networking, and deleting the steps of obtaining and verifying the trust key; B. by reducing the secret key of the fixed network layer, the risk of a hacker intercepting the secret key in the networking stage is reduced; C. the maximum number of the access devices and the trust stack version of the network security layer are set by changing the parameter setting of the software stack. The method can meet the Zigbee scheme which needs large-capacity nodes in the industry, has high practical use value, and effectively expands the application range of the Zigbee scheme.

Description

Method for realizing capacity expansion of number of access devices at Zigbee coordinator end

Technical Field

The invention relates to the technical field of Zigbee wireless communication, in particular to a method for realizing the capacity expansion of the number of access devices at a Zigbee coordinator end.

Background

With the development of the internet of things (IoT) technology, the demand for wireless data communication is getting stronger and stronger in a plurality of fields including industrial automation, smart home and smart energy, and ZigBee is a low-power consumption local area network protocol based on the ieee802.15.4 standard, and is a short-distance and low-power consumption wireless communication technology. Because the Zigbee technology has the advantages of low power, short time delay, high capacity, high safety, etc., and starts to be used in large scale in the industry, according to the data of the industry standards association, the global shipment of Zigbee currently exceeds 5 hundred million pieces, and the growth speed is faster and faster.

The Zigbee network system consists of three kinds of devices or systems with roles of a coordinator (similar to a gateway), a router and a terminal node, wherein the function of the coordinator is mainly responsible for the management of the whole system network, including the allocation of network addresses of the terminal and the routing node in the system; security management, such as issuing and updating of security certificates; and (4) message distribution, for example, the message distribution is responsible for sending the message of the host processor to subordinate nodes and uploading the information of the subordinate nodes to the host processor for processing. The terminal node accesses the coordinator in two modes: one method is to directly access the coordinator in a star topology structure, and the other method is to access the coordinator node after relay routing is performed through the routing node, in the conventional method, the number of nodes which can be supported by the coordinator is generally about 20, and a method for expanding capacity is generally expanded by using a relay routing method, and the method has several disadvantages: firstly, because the number of nodes of a single access point (coordinator or route) is too small (about 20), the efficiency of capacity expansion is not high, and secondly, after the route relay is used, the topological structure is complex, the efficiency and stability of communication are greatly influenced, and especially the condition of introducing multi-stage relay is more obvious.

Disclosure of Invention

The invention aims to overcome the defects in the background art, provides a method for realizing the capacity expansion of the number of the access devices at the Zigbee coordinator end, can meet the Zigbee scheme which needs high-capacity nodes in the industry, has high practical use value, and effectively expands the application range of the Zigbee scheme.

In order to achieve the technical effects, the invention adopts the following technical scheme:

a method for realizing capacity expansion of the number of access devices at a Zigbee coordinator end is realized based on Zigbee3.0, wherein the Zigbee3.0 is a Ti protocol stack, and comprises the following steps:

A. changing the network access process of Zigbee networking, and deleting the steps of obtaining and verifying the trust key;

B. by reducing the secret key of the fixed network layer, the risk of a hacker intercepting the secret key in the networking stage is reduced;

C. the maximum number of the access equipment is set by changing the parameter setting of the software stack;

the method and the process can realize the change of the network access process of the Zigbee network system, delete the process links of acquiring the trust center Key (TCLink Key) initiated by the terminal, issuing the trust center Key by the coordinator, verifying the Key (Verify Key) initiated by the terminal and confirming the Key (Confirm Key) issued by the coordinator, and realize the stable communication of b devices simultaneously accessing the same coordinator.

Further, the step C specifically includes: and changing the definition of the equipment capacity in the network layer macro variable definition file, wherein the equipment capacity is changed from the original quantity a to a quantity b, both a and b are greater than 0, and b is greater than a.

Further, a equals 20 and b equals 80.

Further, the step a specifically includes: in the Zigbee coordinator equipment object file management, the version of the security stack is set to be lower than c, so that the processes of trusting a Key and verifying the Key can not be carried out when terminal equipment is added into the coordinator.

Further, c is equal to 21.

Further, the step B specifically includes: the capacity of the maximum supported trust Key is changed in the security management macro variable definition file, and the capacity is set from the original 40 to 1 and is changed into a subnet fixed network Key to be set on the AES chip.

Compared with the prior art, the invention has the following beneficial effects:

in the technical scheme of the invention, the core problem to be solved is to increase the access capacity of an access point (coordinator or route), the scheme can effectively solve the defects of a general scheme in the industry, the capacity of a single point is improved to 4 times (such as 20 to 80) of the original capacity, further, through a first-level route, the theoretical access capacity upper limit of one coordinator reaches 16 times before capacity expansion (such as 400 before capacity expansion and 6400 after capacity expansion), the node access capacity scale of a unit coordinator is enough to deal with the node number capacity required in most application scenes in the industry, and meanwhile, the application range of the Zigbee communication scheme in an industry application scene is greatly expanded.

Drawings

Fig. 1 is a schematic diagram of interaction flow of zigbee3.0 terminal device joining a coordinator in the prior art.

Fig. 2 is a schematic view of an interaction flow of joining a coordinator by a terminal device after capacity expansion improvement is performed by the method of the present invention in one embodiment.

Detailed Description

The invention will be further elucidated and described with reference to the embodiments of the invention described hereinafter.

Example (b):

as shown in fig. 1, for adding a coordinator interaction flow to zigbee3.0 terminal DEVICEs in the prior art, after deep analysis of zigbee3.0 program code (texas instruments Ti protocol stack), it is found that the capacity of the DEVICE is set to 20 (# define NWK _ MAX _ DEVICE _ LIST 20), according to a conventional idea, if the capacity is to be expanded, the value is directly increased, for example, to 40, but through test, it is found that, in this case, when the number of access DEVICEs is between 20 and 30, the coordinator no longer responds to the Beacon request of the terminal node, which indicates that resources on the coordinator side have been completely used and no redundant node can be accessed. Meanwhile, analysis also shows that the Zigbee3.0 standard protocol uses a two-layer encryption system to ensure the safety of the system.

The first layer is network layer encryption, for a subnet constructed by a coordinator, the coordinator manages a unique network layer key, each terminal node accessing the subnet encrypts transmission of data packets by using the same network key, the network key is dynamically updated, and the coordinator updates the network key to each legal node in the subnet according to a certain period or strategy.

In order to further strengthen the security, the second layer of encryption is the encryption protection of an application layer, for each device, when the device first accesses the network, an application layer key is obtained from the coordinator and used for communication between the device and the coordinator, and in order to ensure smooth communication, the coordinator stores the application layer key of each access device, and the data structure occupies a large memory and a large Flash space, so that the resource consumption is greatly influenced, and the resources are difficult to continue when the access devices are increased.

In practice, for vertical industry applications, cross-brand compatibility is not a business requirement, and meanwhile, it is considered that a network key is distributed through a coordinator when equipment accesses a network, and may be captured and intercepted by a hacker when the equipment accesses the network, but if a distribution mechanism of the network key is changed, the network key is changed into a subnet fixed network key and is fixed when the equipment leaves a factory, and in an AES chip, the possibility of brute force cracking of software and hardware of the equipment can be eliminated, and the hacker cannot obtain the network key in the flow mode through a packet capturing mode.

The embodiment discloses a method for expanding the number of access devices at a Zigbee coordinator, which is implemented based on Zigbee3.0, where Zigbee3.0 in the present solution is a Ti protocol stack, and the method specifically includes the following steps:

the method comprises the following steps: and changing the network access process of the Zigbee networking, and deleting the steps of obtaining and verifying the trust key.

The embodiment specifically includes: in the Zigbee coordinator device object (ZDO) file management, the version of the security stack is set to be lower than 21, so that the processes of trusting Key and verifying Key can not be carried out when terminal equipment is added into the coordinator.

Step two: by reducing the key of the fixed network layer, the risk of the key being intercepted by a hacker in the networking stage is reduced.

The embodiment specifically includes: the capacity of the maximum supported trust Key is changed in the security management macro variable definition file, and is set to 1 from the original 40, and the specific change is as follows:

#if (ZG_BUILD_COORDINATOR_TYPE)

#define ZDSECMGR_TC_DEVICE_MAX 1

#else

#define ZDSECMGR_TC_DEVICE_MAX 0

step three: and the maximum number of the access equipment is set by changing the parameter setting of the software stack.

The embodiment specifically includes: the definition of the capacity of the equipment is changed in the network layer macro variable definition file, which is set to 80 from the original 20, and the # define NWK _ MAX _ DEVICE _ LIST 80 is specifically changed.

Fig. 2 shows that the whole network access flow is greatly changed after the capacity expansion of the method is performed, the link of acquiring a trust center Key (TClink Key) initiated by a terminal, issuing the trust center Key by a coordinator, deleting a verification Key (Verify Key) initiated by the terminal and a confirmation Key (Confirm Key) issued by the coordinator is deleted, and it can be known through practical tests that the method of the present invention realizes that 80 devices simultaneously access to the same coordinator for stable communication.

It will be understood that the above embodiments are merely exemplary embodiments taken to illustrate the principles of the present invention, which is not limited thereto. It will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the spirit and substance of the invention, and these modifications and improvements are also considered to be within the scope of the invention.

Claims

1. A method for realizing capacity expansion of the number of access devices at a Zigbee coordinator end is realized based on Zigbee3.0, and the Zigbee3.0 is a Ti protocol stack, and is characterized by comprising the following steps:

A. changing the network access process of Zigbee networking, and deleting the link of obtaining and verifying the trust key, wherein the link comprises that the version of a security stack is set to be lower than c in the object file management of equipment of a Zigbee coordinator;

B. the method comprises the steps that the risk that a hacker intercepts the secret Key in the networking stage is reduced by reducing the secret Key of a fixed network layer, the capacity of the trust Key which is supported maximally is changed in a security management macro variable definition file, the capacity is set to 1 from 40, and the capacity is changed into a subnet fixed network secret Key and is arranged on an AES chip;

C. the method comprises the steps of changing the definition of the capacity of the access equipment in a network layer macro variable definition file, changing the capacity of the access equipment from the original quantity a to the quantity b, wherein both a and b are greater than 0, and b is greater than a.

2. The method of claim 1, wherein a equals 20 and b equals 80.

3. The method of claim 1, wherein c is equal to 21.