In this second lighting, we invite you to perceive the intricacies of the organization of the radio communication paths and the subtleties of communication links performance, in a wireless network infrastructure whose role is to transmit to an information system, local or remote, the data collected.
What is a wireless network?
Radio communications are based on radio links established between two communicating devices in a transmission / reception process. To build a link, the devices will scan the different radio frequencies of their network to find a signal emitted by a remote device. In a network consisting of several devices, the communication paths are established by a succession of radio links and constitute what is called the topology of the network.
What does the performance of a radio network depend on ?
A radio link can only be established if the ratio of the power of the received signal to the surrounding noise is sufficient to allow the receiver to understand – demodulate – the signal. Thus, for a wireless system to achieve its optimum performance, it is necessary to deploy it in accordance with the recommendations inherent in its mode of operation. Given the reality of the environment, the choice of location and characteristics of radio transmitters and receivers is essential for the proper functioning of a wireless network.
Wireless network seen by HIKOB
Self-organization of communication paths and self-healing of communication links
When commissioning the HIKOB INSTANT system, the devices will automatically seek to connect with each other. In this process, they will choose the radio path at once, the most efficient and with the least radio hops. No manual pairing or manual configuration of equipment is necessary for them to communicate with each other. Thanks to the system self-organization capacity, network scaling is done automatically (no new configuration) by adding new sensors or routers. This mechanism offers a reliable and scalable solution to cover long distances.
Two ways communications
HIKOB wireless network is bidirectional, with similar upstream and downstream speeds. This feature is used to monitor in real time the status of each link in the network and the devices status. It also allows, if necessary, to update firmware settings through the wireless network itself (Over The Air, OTA), or even the firmware itself without intervention on the equipment.
To avoid saturated channels and reinforce the fluidity and robustness of the communications in the event of possible disturbances and/or interferences, HIKOB wireless network protocol relies on the FTDMA (Frequency Time Division Multiple Access) mechanism.This mechanism involves time and frequency multiplexing. It divides the time into slots and assigns one or more communication slots to each device. It also assigns a communication channel to each slot. This channel evolves periodically. Thanks to this double mechanism for assigning the communication channel and the channel usage time, the devices connected to the HIKOB wireless network communicate simultaneously without disturbing each other.
When commissioning the HIKOB INSTANT system, all devices within the network synchronize their clock with the high-precision real-time clock of the gateway. Thus, the communication slots are well respected and exchanges are well done. The fluidity of communications can be ensured.
This synchronization is maintained during the various data exchanges. Thus, the devices in the network remains synchronized with each other. In this way, the information’s of vehicle detections are scheduled on reliable and synchronized timestamps making possible correlations (for example: occupancy rate of a car park, measuring the speed of circulation of a road flow, …).
The power of HIKOB POLAR STAR version
"Preferential connection" option
IKOB wireless network is self-organizing itself to establish the communication paths to the gateway, both the most powerful in terms of radio signal (best RSSI available) and requiring the least radio hopping possible.
During the lapse of time, events can disrupt the established radio links. Depending on the intensity of the disturbance, some radio links may be temporarily cut off. These cuts generate the disconnection of the device concerned.
Thus, in addition to self-organization, HIKOB POLAR STAR software upgrade offers a new option to acon the organization of the network topology. In order to ensure superior network stability, it is possible to define the “preferred parent” to which a device (Integrated HIKOB WISECOW sensor or HIKOB LION router) must connect by default.
When properly chosen, this connection with the “preferred parent” will establish a communication path to the gateway providing a signal quality level in the higher slots and the least possible disconnect risk
"Strengthened robustness” parameter
To prevent possible interferences from third-party wireless networks and / or to allow multiple HIKOB INSTANT systems to operate side-by-side without interfering with one another, HIKOB POLAR STAR offers an advanced presetting system.
Each predefined “Preset Radio” corresponds to a duration of the data exchange frame and a set of radio channels that will be used by the HIKOB network. This list of 35 settings is available via the “HIKOB Network Configuration” function of the HIKOB NETPULSE APP / HIKOB NETPULSE application. Thus, for nearby HIKOB systems to work without interfering, it is sufficient to assign different radio preset numbers to them.
Network Configuration” function _NETPULSE APP P
Accelerated reconnection” mode
HIKOB WISECOW integrated sensors scan the network periodically to connect to the network infrastructure. This operation generates a consumption of the energy resource that it is preferable to conserve for the measurement and the calculations of the detection algorithm. Between two scans, the sensor goes into a standby state to reduce its energy consumption to the lowest level possible.
In the default system configuration, until a connection is established, the time interval between two scans is initially set to 4 seconds. It is doubled after each scan, until it reaches the maximum sleep time of 34 minutes between two scans. This decrease of the scan frequency is set up to preserve the system battery life, especially during the storage phases or when no network is available.
HIKOB POLAR STAR, offers a mode “accelerated reconnection” reducing the maximum duration of sleep between two scans at 1 minute. In the case of applications that require a very low overall operating latency, this mode allows reconnection in a very short time interval.
In this mode, the time between two scans will not exceed one minute during the first half hour. After this half hour, the conventional mechanism is applied again and the time between two scans will increment until it reaches 34 minutes.
HIKOB network reconnection modes available options