Connection Priority

Description

The Connection Priority application demonstrates the utilization of the SPARK Wireless Core in scenarios where multiple connections compete for limited network resources by assigning priorities. This application uses a bidirectional communication between a Coordinator and a Node, showcasing how five connections with varying priorities share link capacity.

Behavior

The Connection Priority application’s schedule consists of two timeslots. The first timeslot is used by the Coordinator’s 3 TX connections to transmit to the Node. The second timeslot is used by the Node’s 2 TX connections to transmit to the Coordinator. A transmitted payload always contains the ID of the connection by which it was sent.

The following diagram illustrates the general structure of the schedule used in this application.

Connection Priority schedule

Figure 19: Connection Priority application’s schedule.

Both devices transmit different types of payloads at varying generation rates, each destined for different TX connections. The variation in payload generation rates serves to illustrate the impact of connection priority on the packet transmission order.

Table 3: Connection Description

Connection ID

Timeslot

Coordinator mode

Node mode

Payload size (bytes)

Payload rate (pps)

Priority

CID0

0

TX

RX

15

500

High

CID1

0

TX

RX

8

400

Medium

CID2

0

TX

RX

15

500

Low

CID3

1

RX

TX

15

750

High

CID4

1

RX

TX

8

200

Medium

Coordinator Device

  • The SW1 switch is used to toggle ON or OFF the data generation on CID0. Data generation is enabled by default.

Table 4: Coordinator User Interface Description

Interface

Name

Description

SW1

CID0 Toggle

Enable/Disable data generation on CID0.

SW2

Reset Stats

Reset the TX and RX statistics.

LED0

N/A

N/A

LED1

N/A

N/A

LED2

N/A

N/A

Node Device

Table 5: Node User Interface Description

Interface

Name

Description

SW1

N/A

N/A

SW2

Reset Stats

Reset the TX and RX statistics.

LED0

N/A

N/A

LED1

N/A

N/A

LED2

N/A

N/A

Configuration

Terminal

Host terminal configuration should be as follows:

  • Speed (baud): 115200

  • Data bits: 8

  • Stop bit: 1

  • Parity: None

  • Flow control: None

The following figure shows the serial interface output of this application.

Serial interface output example

Figure 20: Connection Priority application serial interface output.

See Statistics for more details on the Wireless Core statistics displayed by the application.