SWRA734 December   2021 CC1312PSIP , CC1312R , CC1312R7 , CC1314R10 , CC1352P , CC1352P7 , CC1352R , CC2652P , CC2652P7 , CC2652R , CC2652RB , CC2652RSIP

 

  1.   Trademarks
  2. 1Introduction
  3. 2Benefits of Having Multiple Gateway Support
    1. 2.1 Node Balancing
    2. 2.2 Robustness
    3. 2.3 Extended Coverage and Network Redundancy
  4. 3Current SDK Examples and Coprocessor Configuration
  5. 4Central Gateway
  6. 5Enabling Multiple Gateway Support
    1. 5.1 PAN Coordinator Switching Due to Sync Loss
    2. 5.2 PAN Coordinator Switching Due to a Command Coming From the Central Gateway
  7. 6Basic Implementation of PAN Coordinator Switching
    1. 6.1 PAN Coordinator Switching Due to Sync Loss
    2. 6.2 PAN Coordinator Switching Due to a Command Coming From the Central Gateway
  8. 7Summary
  9. 8References

3 Current SDK Examples and Coprocessor Configuration

Among the TI 15.4-Stack examples included in the SimpleLink SDK, there are three examples which are particularly relevant for this application note. The first two correspond to the sensor and collector examples which showcase the scenario in which a single TI 15.4 network is formed and maintained by a single collector device, and then one or more sensor devices join the network. The third example, on the other hand, corresponds to the co-processor example which could be described as an extension of the collector example that adds gateway capabilities to the PAN coordinator of the TI 15.4 network.

Even though these examples only cover the use-case when there is one collector device acting as PAN coordinator and one or more sensor devices reporting to it, this does not mean that the TI 15.4-Stack cannot be used to form a more complex network with extended network coverage, increased node count, redundancy for nodes in “difficult” RF spots, and node balancing capabilities.

To get a clear understanding of how to do this, first consider the coprocessor configuration described in the TI 15.4-Stack User’s Guide.

In this configuration, the protocol stack runs on a CC13xx or CC26xx device while the application is executed on an external MPU or MCU. Because the host application executes on an external MPU or MCU, it can run protocol stack layers over the IEEE 802.15.4 e/g MAC and PHY (for example, generic IP over 6LoWPAN, Zigbee™ IP, or Zigbee Pro) making the co-processor configuration suitable for applications that require long-range wireless connectivity. In simple terms, in the co-processor configuration the collector device operates not only as a TI 15.4 PAN coordinator but also as a local gateway capable of communicating with other local gateways.

Figure 3-1 High-Level Software Architecture of the TI 15.4-Stack Coprocessor Configuration

Consequently, if a single source, which from now on will be referred as central gateway, coordinates a group of local gateways, it is possible to create a larger network that is composed of many TI 15.4 local networks and that is capable of supporting the previously mentioned network features.