Smart phone ad hoc or smart phone ad hoc networks (SPANs) evolve from the underlying concept, architecture and technology behind a wireless ad hoc network. A smart phone is a device. Once embedded with ad hoc networking technology, a smart phone can create ad hoc networks among other devices. Smart phone ad hoc networks leverage the existing hardware (primarily Bluetooth and Wi-Fi) in commercially available smartphones to create peer-to-peer networks without relying on cellular carrier networks, wireless access points, or traditional network infrastructure. SPANs use the mechanism behind Wi-Fi ad-hoc mode, which allows phones to talk directly among each other, through a transparent neighbor and route discovery mechanism.
SPANs differ from traditional hub and spoke networks, such as Wi-Fi Direct, in that they support multi-hop routing (ad hoc routing) and relays and there is no notion of a group leader, so peers can join and leave at will without destroying the network.
Features
- Capable of going off-grid and enabling peer-to-peer communications without relying on cellular carrier networks, wireless access points, or traditional network infrastructure.
- Optional Internet access through gateway devices, such as mobile hotspots in the mesh.
- Optional stationary or portable infrastructures such as routers, mesh extenders, or other non-phone hardware.
- Leverage the devices that people carry on their person and use every day.
- Primarily use Bluetooth and Wi-Fi since the cellular spectrum is licensed and controlled by cellular providers and FCC regulations.
- Set up and tear down are on-demand. Join and leave at will.
- Routing protocol may be implemented at the Network Layer or Link Layer.
- Often requires rooting a device and making modifications to the operating system, kernel, or drivers.
Threats to telcos
The ad hoc networking technology operating on Wi-Fi ad hoc mode, at the unlicensed ISM band of 2.4Â GHz may result in profit loss by cellular carriers since ISM band is free and unlicensed while cellular carriers operate on licensed band at 900Â MHz, 1200Â MHz, 1800Â MHz, etc. This has the potential to threaten telecommunication operators (telcos). Smart phone mobile ad hoc networks can operate independently and allow communications among smart phones users without the need for any 3G or 4G LTE signals to be present. Wi-Fi ad hoc mode was first implemented on Lucent WaveLan 802.11a/b on laptop computers. The technology success is now carried forward and used in smart phones, since Wi-Fi is present and embedded in all smart phones today.
Important applications
- Developing nations where network infrastructure doesn't exist.
- Protests where government entities monitor or disable network infrastructure.
- Natural disasters or terrorist incidents where existing network infrastructure is overloaded, destroyed, or compromised.
- Temporary Large-scale events such as festivals where huge scale is needed for short period of time
Below are some of the recent applications of smart phone ad hoc networks in real life:
- 2014 â€" in Iraq following government restrictions on internet use, users use the technology to communicate
- 2014 â€" Hong Kong Protests in China used Firechat to communicate
- 2015 â€" Leaders of Anti-government protests in Russia in December 2014 urged their followers to install firechat
APPLE multipeer connectivity
In APPLE Inc. iPhones released with iOS version 7.0 and higher, multipeer connectivity APIs (application programmable interfaces) are enabled and provided to allow APPLE iphones to operate in peer-to-peer ad hoc mesh networking mode. This means iphones can now talk to each other without using a cellular signal or connection. Currently, APPLE uses multipeer to allow one to send photos and large files (up to GB) to peers. This application is called AirDrop and has been gaining popularity. With 700+ millions of iPhones being used globally, ad hoc peer-to-peer networks will gain pervasive presence almost instantly.
Projects
- The SPAN Project
- The Serval Project
- Commotion Wireless
- FireChat
- MapMe.io
- Locayt
Device manufacturer support
- iOS Multipeer Connectivity Framework
See also
- Mobile ad hoc network
- Wireless ad hoc network
- Wireless mesh network