Smartphone ad hoc networks (SPANs; also ''smart phone ad hoc networks'') are
wireless ad hoc network
A wireless ad hoc network (WANET) or mobile ad hoc network (MANET) is a decentralized type of wireless network. The network is ad hoc because it does not rely on a pre-existing infrastructure, such as routers or wireless access points. Instead, ...
s that use
smartphone
A smartphone is a mobile phone with advanced computing capabilities. It typically has a touchscreen interface, allowing users to access a wide range of applications and services, such as web browsing, email, and social media, as well as multi ...
s. Once embedded with ad hoc networking technology, a group of smartphones in close proximity can together create an ad hoc network. Smart phone ad hoc networks use the existing hardware (primarily
Bluetooth
Bluetooth is a short-range wireless technology standard that is used for exchanging data between fixed and mobile devices over short distances and building personal area networks (PANs). In the most widely used mode, transmission power is li ...
and
Wi-Fi
Wi-Fi () is a family of wireless network protocols based on the IEEE 802.11 family of standards, which are commonly used for Wireless LAN, local area networking of devices and Internet access, allowing nearby digital devices to exchange data by ...
) in commercially available smartphones to create peer-to-peer networks without relying on cellular carrier networks, wireless access points, or traditional network infrastructure. Wi-Fi 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
A hub is the central part of a wheel that connects the axle to the wheel itself.
Hub, HUB, or hubs may refer to:
Geography Pakistan
* Hub Tehsil, Balochistan, an administrative division of southern pakistan
** Hub, Balochistan, capital city o ...
networks, such as
Wi-Fi Direct
Wi-Fi Direct is a Wi-Fi standard for wireless connections that allows two devices to establish a direct Wi-Fi connection without an intermediary wireless access point, Router (computing), router, or Internet connection. Wi-Fi Direct is single-hop ...
, in that they support
multi-hop routing
Multi- hop routing (or multihop routing) is a type of communication in radio networks in which network coverage area is larger than radio range of single nodes. Therefore, to reach some destination a node can use other nodes as relays.
Since the ...
(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.
SPANs are useful under circumstances when the regular network is overloaded or unavailable, such as conferences, music festivals, or natural disasters, and have been popular in Australia and
Latin America. They are popular with youth in the
United States
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...
as a way to save money, as data sent directly from device to device is free.
SPANs started being used in
Iraq
Iraq, officially the Republic of Iraq, is a country in West Asia. It is bordered by Saudi Arabia to Iraq–Saudi Arabia border, the south, Turkey to Iraq–Turkey border, the north, Iran to Iran–Iraq border, the east, the Persian Gulf and ...
in 2014 to bypass government restrictions on Internet usage,
in the
2014
The year 2014 was marked by the surge of the Western African Ebola epidemic, West African Ebola epidemic, which began in 2013, becoming the List of Ebola outbreaks, most widespread outbreak of the Ebola, Ebola virus in human history, resul ...
and
2019–20 Hong Kong protests,
in 2015 in anti-government protests in
Russia
Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...
.
They have also been used by protestors in Taiwan, Iran, and Syria.
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 Mesh or 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
Wi-Fi () is a family of wireless network protocols based on the IEEE 802.11 family of standards, which are commonly used for Wireless LAN, local area networking of devices and Internet access, allowing nearby digital devices to exchange data by ...
ad hoc mode, at the unlicensed
ISM band
The ISM radio bands are portions of the radio spectrum reserved internationally for ''industrial, scientific, and medical'' (ISM) purposes, excluding applications in telecommunications.
Examples of applications for the use of radio frequency (RF ...
of 2.4 GHz may result in profit loss by cellular carriers since ISM band is free and unlicensed while cellular carriers operate on licensed band at 900 MHz, 1200 MHz, 1800 MHz, etc. This has the potential to threaten telecommunication operators (telcos). Smart phone
mobile ad hoc network
A wireless ad hoc network (WANET) or mobile ad hoc network (MANET) is a decentralized type of wireless network. The network is ad hoc because it does not rely on a pre-existing infrastructure, such as router (computing), routers or wireless acces ...
s can operate independently and allow communications among smart phones users without the need for any
3G or
4G LTE
LTE may refer to:
Science and technology
* LTE (telecommunication) (Long-Term Evolution), a mobile telephony standard
** LTE Advanced, an enhancement
** LTE Advanced Pro, a further enhancement
* Compaq LTE, a line of laptop computers
* Leukotrie ...
signals to be present. Wi-Fi ad hoc mode was first implemented on Lucent
WaveLAN 802.11a/b on laptop computers. Since Wi-Fi is present and embedded in all smart phones today, this earlier technology was adapted for smartphones.
Usage
Smartphone ad hoc networks may be useful in situations that include:
* 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 a huge scale is needed for short period of time.
Real-life usage of smart phone ad hoc networks
* 2014 – in
Iraq
Iraq, officially the Republic of Iraq, is a country in West Asia. It is bordered by Saudi Arabia to Iraq–Saudi Arabia border, the south, Turkey to Iraq–Turkey border, the north, Iran to Iran–Iraq border, the east, the Persian Gulf and ...
following government restrictions on internet use, users use the technology to communicate
* 2014 –
Hong Kong protests calling for more democracy used
FireChat to communicate
* 2015 – Leaders of anti-government protests in Russia in December 2014 urged their followers to install FireChat
* 2015 – By 2015, millions of teenagers and school children in the United States had started using smart phone ad hoc networks to chat and communicate, without the need for Wi-Fi or cellular signals.
* 2019 – During the
2019–20 Hong Kong protests that started in opposition to a proposed modification of an extradition law,
Bridgefy, a smartphone ad hoc network app apparently running on
Bluetooth Mesh, was used to communicate during protests in a way that minimised tracking and interference by authorities.
Operating system
Apple Multipeer Connectivity
In
Apple Inc.
Apple Inc. is an American multinational corporation and technology company headquartered in Cupertino, California, in Silicon Valley. It is best known for its consumer electronics, software, and services. Founded in 1976 as Apple Comput ...
iPhone
The iPhone is a line of smartphones developed and marketed by Apple that run iOS, the company's own mobile operating system. The first-generation iPhone was announced by then–Apple CEO and co-founder Steve Jobs on January 9, 2007, at ...
s 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 in 2017 had started gaining in popularity. With 700+ millions of iPhones being used globally, ad hoc peer-to-peer networks will gain pervasive presence almost instantly.
Android phone ad hoc networks
By merging the Linux Wireless Extension API with parts of the
Android software stack, a modified version of Android can enable the ability to harness the ad hoc routing, communications and networking features of the onboard Wi-Fi chip. This empowers millions of Android phones with ad hoc mesh connectivity and networking capabilities.
Software implementations
Software packages that implement smartphone ad hoc networks include
GPL-licensed
Serval Project over Bluetooth or WiFi; GPL-licensed
Commotion Wireless;