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Instant setup. Evolutionary Technology. Proven HD quality. Try ConXhub’s mobile VOIP business phone system today.

ConXhub allows you to use your Personal mobile for business & Protect your privacy!

Carrying 2 or more phones?... ditch the second mobile, bin the desk phone, and massively reduce calling costs... plus a whole lot of other VoIP’esque benefits.

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30,000+ companies trust ConXhub's 5G mobile - centric cloud phone system to support their growth

“During our first business quarter with ConXhub, missed call rates decreased by 27% while outbound pick up rates increased by 77%”

Glenn Burgess , Head of Sales at Pow New Media Ltd

Mobile VoIP

Mobile VoIP is an efficient, low-cost way to communicate using your cell phone and the services provided by your home or business VoIP provider.

Benefits of Mobile VoIP

Mobile VoIP phone users can benefit from voice over IP services to lower their monthly phone bills. Some cell phone users will take advantage of mobile VoIP phone service to eliminate their voice plans. Using mobile VoIP can result in a simple, data-plan-only relationship with your cell phone carrier. Choosing a data-only plan can result in significant savings.

Benefits for Businesses

Mobile VoIP phones are increasingly popular not only with individuals but also with businesses looking to streamline their operations and lower their overhead. Businesses with personnel on the road with company-issued cell phones find mobile VoIP service to be a cost-effective solution.

Mobile VoIP phones can be used by individuals or by businesses to improve the quality, efficiency, and cost of their overall communications. Businesses and individuals save money on international calls when using mobile VoIP phones. Country-to-country calls are billed at inexpensive local area rates, and the business traveller or tourist isn’t slammed with roaming charges.

Using a mobile VoIP app or mobile VoIP service can also add greater functionality to your cell phone. Mobile VoIP apps can also add new and useful features such as group chat, video chat, or 4-way calling. These features can be useful tools in business communications. VoIP smartphone apps, such as those included with 3CX, allow employees to answer calls to their office extension from their mobile phone wherever they are. This is a great advantage for traveling or remote employees.


Mobile VoIP Apps for Android and iOS are the perfect extension of your business phone system and transform your mobile devices into an essential, central component of your everyday workflows.

Mobile VoIP apps are continuously tested and upgraded to offer to offer a seamless communications experience with the latest in mobile communications functionality and enable users to work from anywhere and provide instant access to all their must have telephony and collaboration tools while PUSH notification support saves phone battery life whilst ensuring maximum availability in standby mode.

  • “PUSH” notifications save mobile device battery life.
  • Secure communication with SIP TLS encryption.
  • Integrated SIP softphone and GSM fallback.
  • No additional add-on licensing required.

Take Your Office With You

Moving around the office, working from home or on a business trip? Take your office extension with you where ever you go and never miss a call again with a mobile VoIP app. With the fully integrated SIP softphone, users can make and receive business calls using their office extension over 3G, LTE and WiFi networks. The inbuilt GSM fallback function ensures calls are routed via the GSM network should a stable internet connection not be available.

  • Make and receive office calls on your smartphone at no extra cost.
  • One number concept converges mobile and fixed line communications.
  • Eliminates the need to share private mobile phone numbers.
  • Perfect for BYOD / CYOD mobile communications.


Mobile UCC – Anywhere, Anytime Collaboration

Access all your essential collaboration tools directly on your Android and iOS smartphone and tablet. A mobile UCC app ensures that you and your team can connect and communicate from anywhere, keeping your team productive. The unified “look & feel” across the desktop and mobile UCC apps ensure optimal user-friendliness and simple access to all your UCC collaboration tools (Instant Messaging, Team Chat, File Sharing) and Audio and Video Conferencing tools.

  • Phone, Chat, File Sharing, Audio & Video Conferencing all in one app.
  • Search fully synchronised company phone books, chat and call logs.
  • Check colleague availability and manage your status from anywhere.
  • Ideal for remote and Home Office working.


Accessing Mobile VoIP

Cell phone users can use mobile VoIP service on their phone with the addition of mobile VoIP software. These are apps offered by VoIP phone service providers customers may already be using at home or at work, such as Vonage or 3CX, or standalone mobile VoIP apps such as Skype, Vyke, or Truphone.

Some services, such as Truphone, also offer an entire mobile VoIP network by combining a SIM (Subscriber Identity Module) card and an app together. (The SIM card contains all the information needed to identify network subscribers.) One functions where the other doesn’t, depending on the circumstance, to offer a comprehensive mobile VoIP network service.

To use this kind of mobile VoIP function, along with other similar services, you need an unlocked handset. Most mobile VoIP apps, however, piggyback onto your existing data plan and do not require unlocking.


How Does Mobile VoIP Work?

Mobile VoIP works with a cell phone’s 3G, 4G, GSM, or another Internet service to send voice calls as digital signals over the Internet using voice over IP technology. Mobile VoIP phones can also take advantage of WiFi hotspots to eliminate the calling costs of a cellular voice or data plan.

Mobile VoIP or simply mVoIP or even MoIP is an extension of mobility to a Voice over IP network. Two types of communication are generally supported: cordless/DECT/PCS protocols for short range or campus communications where all base stations are linked into the same LAN, and wider area communications using 3G/4G protocols.

There are several methodologies that allow a mobile handset to be integrated into a VoIP network. One implementation turns the mobile device into a standard SIP client, which then uses a data network to send and receive SIP messaging, and to send and receive RTP for the voice path. This methodology of turning a mobile handset into a standard SIP client requires that the mobile handset support, at minimum, high speed IP communications.

Another implementation of mobile integration uses a soft-switch like gateway to bridge SIP and RTP into the mobile network’s SS7 infrastructure. In this implementation, the mobile handset continues to operate as it always has (as a GSM or CDMA based device), but now it can be controlled by a SIP application server which can now provide advanced SIP-based services to it. Several vendors offer this kind of capability today.

By using VoIP, mobile VoIP phone users — especially smartphone users — can benefit from lower costs when calling, texting, or other common smartphone activities. Digital data transmission using VoIP is also typically faster, as the data is spread out over multiple packets, each taking the fastest route to its intended destination.

Using a mobile VoIP phone with WiFi hotspot access can also reduce a mobile VoIP phone user’s costs by sidestepping the carrier’s expensive 3G service altogether. For instance, with a cellular carrier’s monthly data plan, callers can easily exceed bandwidth maximums, incurring overage charges. Tapping into WiFi hotspots with mobile VoIP software reduces that risk and extends the lifespan of the monthly data allotment.

A mobile VoIP phone service can eliminate the need for a basic voice plan, as well as optional (and costly) text add-ons. With a mobile VoIP phone, cell phone users can enjoy more flexibility in calling times than a cellular voice plan provides, with fewer restrictions. VoIP mobile phone service means that a mobile VoIP user can make unlimited inexpensive or free calls using voice over IP technology at any time.

Mobile VoIP users don’t need to worry about the limitations associated with cell phone calling plans, such as:

  • Anytime minutes
  • Night or weekend minutes
  • Rollover minutes
  • Roaming charges
  • Incoming call charges
  • Messaging limits

Mobile-to-mobile calling (check with your mobile VoIP provider, some do treat in-network calls differently)

Mobile VoIP phone users can also take advantage of the additional, integrated features a mobile VoIP app supports. This includes high-bandwidth activities such as group chat and video chat. Accessing these functions without mobile VoIP software (by fring or Talkonaut, for instance), typically requires a separate app, and using it could impact or exceed monthly text and bandwidth


Mobile VoIP will require a compromise between economy and mobility. For example, voice over Wi-Fi offers potentially free service but is only available within the coverage area of a single Wi-Fi access point. Cordless protocols offer excellent voice support and even support base station handoff, but require all base stations to communicate on one LAN as the handoff protocol is generally not supported by carriers or most devices.

High speed services from mobile operators using EVDO rev A or HSPA may have better audio quality and capabilities for metropolitan-wide coverage including fast handoffs among mobile base stations, yet may cost more than Wi-Fi-based VoIP services.


Industry history


Early experiments proved that VoIP was practical and could be routed by Asterisk even on low-end routers like the Linksys WRT54G series. Suggesting a mesh network (e.g. WDS) composed of such cheap devices could similarly support roaming mobile VoIP phones. These experiments, and others for IP roaming such as Sputnik, were the beginning of the 5G protocol suite including IEEE 802.21 and IEEE 802.11u. At this time, some mobile operators attempted to restrict IP tethering and VoIP use on their networks, often by deliberately introducing high latency into data communications making it useless for voice traffic.


In the summer of 2006, a SIP (Session Initiation Protocol) stack was introduced and a VoIP client in Nokia E-series dual-mode Wi-Fi handsets (Nokia E60, Nokia E61, Nokia E70). The SIP stack and client have since been introduced in many more E and N-series dual-mode Wi-Fi handsets, most notably the Nokia N95 which has been very popular in Europe. Various services use these handsets.


In spring 2008 Nokia introduced a built in SIP VoIP client for the very first time to the mass market device (Nokia 6300i) running Series 40 operating system. Later that year (Nokia 6260 Slide was introduced introducing slightly updated SIP VoIP client. Nokia maintains a list of all phones that have an integrated VoIP client in Forum Nokia.

Aircell’s battle with some companies allowing VoIP calls on flights is another example of the growing conflict of interest between incumbent operators and new VoIP operators.


By January 2009 OpenWRT  was capable of supporting mobile VoIP applications via Asterisk running on a USB stick. As OpenWRT runs on most Wi-Fi routers, this radically expanded the potential reach of mobile VoIP applications. Users reported acceptable results using G.729 codecs and connections to a “main NAT/Firewall router with a NAT=yes and canreinvite=no.. As such, my asterisk will stay in the audio path and can’t redirect the RTP media stream (audio) to go directly from the caller to the callee.” Minor problems were also reported: “Whenever there is an I/O activities … i.e. reading the Flash space (mtdblockd process), this will create some hick-ups (or temporarily losing audio signals).” The combination of OpenWRT and Asterisk is intended as an open source replacement for proprietary PBXes.

The company xG Technology, Inc. had a mobile VoIP and data system operating in the license-free ISM 900 MHz band (902 MHz – 928 MHz). xMax is an end-to-end Internet Protocol (IP) system infrastructure that is currently deployed in Fort Lauderdale, Florida.


In January 2010 Apple Inc. updated the iPhone developer SDK to allow VoIP over cellular networks. iCall  became the first App Store app to enable VoIP on the iPhone and iPod Touch over cellular 3G networks.

In second half of 2010 Nokia introduced three new dualmode Wi-Fi capable Series40 handsets (Nokia X3-02, Nokia C3-01 and, Nokia C3-01 Gold Edition) with integrated SIP VoIP that supports HD voice (AMR-WB).


The mainstreaming of VoIP in the small business market led to the introduction of more devices extending VoIP to business cordless users.

Panasonic introduced the KX-TGP base station supporting up to 6 cordless handsets, essentially a VoIP complement to its popular KX-TGA analogue phones which likewise support up to 4 cordless handsets. However, unlike the analogue system which supports only four handsets in one “conference” on one line, the TGP supports 3 simultaneous network conversations and up to 8 SIP registrations (e.g. up to 8 DID lines or extensions), as well as an Ethernet pass-through port to hook up computers on the same drop. In its publicity Panasonic specifically mentions Digium (founded by the creator of Asterisk), its product Switchvox and Asterisk itself.

Several router manufacturers including TRENDnet and Netgear released sub-$300 Power over Ethernet switches aimed at the VoIP market. Unlike industry standard switches that provided the full 30 watts of power per port, these allowed under 50 watts of power to all four PoE ports combined. This made them entirely suitable for VoIP and other low-power use (Motorola Canopy or security camera or Wi-Fi APs) typical of a SOHO application, or supporting an 8-line PBX, especially in combination with a multi-line handset such as the Panasonic KX-TGP (which does not require a powered port).

Accordingly, by the end of 2011, for under US$3000 it was possible to build an office VoIP system based entirely on cordless technology capable of several hundred metres reach and on Power over Ethernet dedicated wired phones, with up to 8 DID lines and 3 simultaneous conversations per base station, with 24 handsets each capable of communicating on any subset of the 8 lines, plus an unlimited number of softphones running on computers and laptops and smartphones. This compared favourably to proprietary PBX technology especially as VoIP cordless was far cheaper than PBX cordless.

Cisco also released the SPA112, an Analogue Telephone Adapter (ATA) to connect one or two standard RJ-11 telephones to an Ethernet, in November 2011, retailing for under US$50. This was a competitive response to major cordless vendors such as Panasonic moving into the business VoIP cordless market Cisco had long dominated, as it suppressed the market for the cordless makers’ native VoIP phones and permitted Cisco to argue the business case to spend more on switches and less on terminal devices. However, this solution would not permit the analogue phones to access every line of a multi-line PBX, only one hardwired line per phone.

As of late 2011, most cellular data networks were still extremely high latency and effectively useless for VoIP. IP-only providers such as Voipstream had begun to serve urban areas, and alternative approaches such as OpenBTS (open source GSM) were competing with mobile VoIP.

In November 2011, Nokia introduced Nokia Asha 303 with integrated SIP VoIP client that can operate both over Wi-Fi and 3G networks.


In February 2012, Nokia introduced Nokia Asha 302 and in June Nokia Asha 311 both with integrated SIP VoIP client that can operate both over Wi-Fi and 3G networks.


By September 2014, mobile-enabled VoIP (VoLTE) had been launched by T-Mobile US across its national network and by AT&T Mobility in a few markets.  Verizon plans to launch its VoLTE service “in the coming weeks,” according to media reports in August, 2014. It provides HD Voice, which increases mobile voice quality, and permits optional use of video calling and front and rear-facing cameras. In the future, Verizon’s VoLTE is expected to also permit video sharing, chat functionality, and file transfers.

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