It has been 3 months since June, a freshman majoring in communication technology, entered the university. June came across with her teacher Professor Andy.
Hi June，how do you like your cellphone?
I can not live without my cellphone.
Does it work perfectly every day?
Most of the time. However, I went to a concert last weekend, there were tens of thousands of people, it took longer time than usual when I sent the onsite pictures to my friends. I’m a little disappointed.
It seems that if I’m in a crowded place or remote area, sometimes the signals are not very good.
Me too. A bit slower network doesn’t matter too much for us, but when the policeman or rescue team go to the place with poor Internet coverage or go where happens to be hit by an earthquake...
We hope not, but if it really happens, they do really need reliable communication equipment to quickly restore the on-site communication. Right?
Yes, absolutely. Because time is limited and the rescue work will be very tough,
what can they do?
There is a wireless communication technology especially suitable for this kind of scenario.
It's Wireless Ad-Hoc Network technology.
Wireless Ad-Hoc Network (WANET) is an independent peer-to-peer wireless network autonomously formed of multiple mobile nodes on a dynamic basis. Unlike traditional wireless networks, the WANET is self-healing and requires no fixed infrastructure or centralized control. In the WANET, all the mobile nodes are generally self-powered and may act as a receiver, a sender, or a router depending on the rapid and unpredictable change in network topology. Thanks to its dynamic and flexible architecture, the WANET can be deployed flexibly and efficiently regardless of constraints such as geographical location. Thus, WANET is particularly suited to the emergency and rescue situations where the fixed infrastructure is not available such as earthquake or fire rescue. The WANET has the following inherent characteristics.
WANET is a peer-to-peer network without a control center. In other words, all the nodes are equal, and freely joining or leaving the network. The failure of any node will not affect the operation of entire network.
All the mobile nodes in WANET can quickly and automatically form an independent network after power-on, without the need to pre-set the network infrastructure. They can coordinate with each other based on layer protocols and distributed algorithm.
The WANET is unlike the traditional fixed network in which the routing device such as a router is required. When a node tries to send information to other nodes which is out of its communication range, the packet can be forwarded via one or more intermediate nodes.
The WANET has a dynamic network topology. Nodes in WANET are free to move randomly, and can turn on or off at any time. Thus, the network topology is changed accordingly.
Adopting the wireless interconnection technology, Hytera WANET products provide multi-hop links to achieve voice and data communication in an extended coverage, support up to 31 nodes for networking and various topologies including chain, tree, and mesh, realize flexible deployment according to the onsite conditions, and support dynamic networking, i.e., nodes for networking can move as wish.
Hytera WANET products are rigorously tested for compliance to the stringent ingress protection (IP). They withstand harsh environments such as dust and high temperature. In order to be applied in various kinds of conditions, multiple mounting options are provided, such as man packed, pole mounted, wall mounted and vehicle mounted. Hytera WANET products adopt Digital Mobile Radio (DMR) standards, thus are compatible with any DMR radios and systems. Working with the on-site command and control equipment, these products get the image and voice from the scene, and then transmit them back to the command center, improving situational awareness for commander.
When earthquake, typhoon or other disaster strikes, the fixed communication network equipment may be completely destroyed or couldn't work properly. In this case, wireless Ad-Hoc network, which does not rely on any fixed network facilities, can be widely used. In the remote mountains, jungles or major events, the Wireless Ad-Hoc Network technology can also provide reliable communication network, allowing the voice to be heard at every corner!
That's great! No more worrying about losing touch with my partners!
Well, different technologies apply to different scenarios. I hope the technology sharing is useful for you today.
Thank you so much, Professor.