Non-IP cellular socket
CellularNonIPSocket class hierarchy
The CellularNonIPSocket class provides, through standard socket send and recv member functions, the ability to send and receive 3GPP non-IP datagrams (NIDD) using our cellular IoT feature. This feature is implemented in the ControlPlane_netif class.
The constructor takes no parameters. To initialize the socket on a specified NetworkInterface, you must call the open method, which takes a CellularContext pointer.
CellularContext sets up the modem into the Control Plane optimization mode of operation if it is requested and if the cellular network supports it.
Control plane optimization is a new feature for cellular IoT (CIoT). With it, the device can use cellular control channels for data communications, to save power and resources by using less radio signaling.
Note: Note: Non-IP use usually requires integration to a cellular operator messaging service. The service supports a web API to send to and receive the non-IP using devices.
You can request Control Plane optimization mode either with CellularDevice's create_context or by configuring it in the cellular mbed_lib.json:
{
"name": "cellular",
"config": {
"control-plane-opt": {
"help": "Enables control plane CIoT EPS optimisation",
"value": true
}
}
}
CellularNonIPSocket class reference
| Public Member Functions | |
| ~CellularNonIPSocket () override | |
| Destroy the socket. More... | |
| CellularNonIPSocket () | |
| Creates a socket. More... | |
| nsapi_error_t | open (mbed::CellularContext *cellular_context) |
| Opens a socket on the given cellular context. More... | |
| nsapi_error_t | open (mbed::ControlPlane_netif *cp_netif) |
| Opens a socket that will use the given control plane interface for data delivery. More... | |
| nsapi_error_t | close () override |
| Closes socket. More... | |
| nsapi_size_or_error_t | send (const void *data, nsapi_size_t size) override |
| Send data over a control plane cellular context. More... | |
| nsapi_size_or_error_t | recv (void *data, nsapi_size_t size) override |
| Receive data from a socket. More... | |
| void | set_blocking (bool blocking) override |
| Set blocking or non-blocking mode of the socket. More... | |
| void | set_timeout (int timeout) override |
| Set timeout on blocking socket operations. More... | |
| void | sigio (mbed::Callback< void()> func) override |
| Register a callback on state change of the socket. More... | |
| nsapi_error_t | connect (const SocketAddress &address) override |
| NOT APPLICABLE. More... | |
| Socket * | accept (nsapi_error_t *error=NULL) override |
| NOT APPLICABLE. More... | |
| nsapi_error_t | listen (int backlog=1) override |
| NOT APPLICABLE. More... | |
| nsapi_error_t | setsockopt (int level, int optname, const void *optval, unsigned optlen) override |
| NOT APPLICABLE. More... | |
| nsapi_error_t | getsockopt (int level, int optname, void *optval, unsigned *optlen) override |
| NOT APPLICABLE. More... | |
| nsapi_error_t | getpeername (SocketAddress *address) override |
| NOT APPLICABLE. More... | |
| nsapi_size_or_error_t | sendto (const SocketAddress &address, const void *data, nsapi_size_t size) override |
| NOT APPLICABLE. More... | |
| nsapi_size_or_error_t | recvfrom (SocketAddress *address, void *data, nsapi_size_t size) override |
| NOT APPLICABLE. More... | |
| nsapi_error_t | bind (const SocketAddress &address) override |
| NOT APPLICABLE. More... | |
CellularNonIPSocket example
The following code demonstrates how to create and use a cellular non-IP socket:
/*
* Copyright (c) 2006-2020 Arm Limited and affiliates.
* SPDX-License-Identifier: Apache-2.0
*/
#include "mbed.h"
#include "CellularNonIPSocket.h"
#include "CellularDevice.h"
// Network interface
NetworkInterface *iface;
int main()
{
// Bring up the cellular interface
iface = CellularContext::get_default_nonip_instance();
MBED_ASSERT(iface);
// sim pin, apn, credentials and possible plmn are taken automatically from json when using NetworkInterface::set_default_parameters()
iface->set_default_parameters();
printf("Cellular Non-IP Socket example\n");
if (NSAPI_ERROR_OK != iface->connect() || NSAPI_STATUS_GLOBAL_UP != iface->get_connection_status()) {
printf("Error connecting\n");
return -1;
}
CellularNonIPSocket sock;
nsapi_error_t retcode = sock.open((CellularContext *)iface);
if (retcode != NSAPI_ERROR_OK) {
printf("CellularNonIPSocket.open() fails, code: %d\n", retcode);
return -1;
}
const char *send_string = "TEST";
if (0 > sock.send((void *) send_string, sizeof(send_string))) {
printf("Error sending data\n");
return -1;
}
printf("Success sending data\n");
char recv_buf[4];
if (0 > sock.recv((void *)recv_buf, sizeof(recv_buf))) {
printf("Error receiving data\n");
return -1;
}
printf("Success receiving data\n");
// Close the socket and bring down the network interface
sock.close();
iface->disconnect();
return 0;
}