Mobile VoIP Phone

A mobile VoIP phone is a cell phone with an Internet connection that can be used to make Voice over IP phone calls, rather than relying on the phone carrier's cellular network to transport voice traffic.

VoIP mobile phone service converts the electrical signal of the call into digitized data packets that are transmitted over the Internet, resulting in cheaper and more efficient mobile phone service.

Mobile VoIP phone service is an inexpensive way to use a cell phone keep in touch with friends, family, and business colleagues by using the Internet for voice calls as well as for data.

Many VoIP apps such as Viber, Line2, and Skype can also be used with 3G/4G Internet data connections, and not just WiFi.

With a mobile phone, a VoIP app/service, and a WiFi hotspot, mobile phone users can access low-cost VoIP services such as free texting, free long distance, free in-network calls, and low-cost international calls.

What is a Mobile VoIP Phone?

A 'mobile VoIP phone' is sort of a roundabout way to describe how to use VoIP phone service with a standard, Internet-connected mobile phone. Because the North American cell phone market is still centered around (mostly) long-term contracts with carriers that often dictate the type of phone that you can use (think iPhone and AT&T), the most common type of mobile VoIP phone is therefore a cell phone with a VoIP app (sometimes called a softphone) downloaded and installed.

True Mobile VoIP Phones

There are, however, some rare VoIP mobile phone service providers such as Republic Wireless that offer a truly mobile VoIP phone. Republic Wireless manufactures a hybrid phone with a built-in VoIP app (no downloads necessary), and supplies VoIP phone service through its own carrier network. There's currently only one phone model available, the LG Optimus, however.

The Republic Wireless mobile VoIP phone uses WiFi first, and switches to its cellular network if there is no WiFi available. In comparison, Line2 is a VoIP provider offering a similarly adaptable service — switching from WiFi to 3G/4G, and lastly to cellular. Line2, however, is a VoIP app available for download and installation.

With built-in VoIP, not only is there no need to download and install an app, but there's no need to launch one, either. And while some VoIP apps — even free apps with free VoIP service — require registration, a separate phone number for VoIP calls, or a PIN number to access service, the built-in VoIP service of the Republic Wireless mobile VoIP phone means you just use the phone as you would any mobile phone. No muss, no fuss.

Softphones: The Mobile VoIP App

A softphone is a piece of software that emulates and/or functions as a phone. A softphone can be downloaded and installed onto any Internet-connected device, such as a computer, iPad, or cell phone. A softphone usually features familiar graphic and audio cues that support ease of use by users young and old, such as a keypad, phone icons, and dialing and ringing sounds. Mobile phone VoIP apps are therefore softphones.

Most of these VoIP apps are downloaded by mobile phone users from iTunes, Google Play, the Android Marketplace, or wherever cell phone users might find apps most appropriate for their phone's operating system.

There are many free or low-cost downloadable mobile phone VoIP apps that offer free or inexpensive subscriber-based services. For instance:

  • TruPhone
  • fring
  • Plingm

There are also many apps that are extensions to paid residential or business VoIP subscriptions. For instance, Vonage offers an app for iPhone and Android smartphones.'s VoIP app is included as part of its business plans, and supports most of the standard features of its hosted business PBX service.

Most cell phone VoIP apps are created to work with a specific VoIP service provider. For instance, the Line2 app works with a monthly Line2 subscription, and the Skype and Vippie apps only offer free in-network calling (out-of-network calls incur low rates).

There are also mobile VoIP phone apps, or softphones, that are available for use with multiple service providers, however. Many of these are business-oriented softphones. These mobile VoIP softphones are generally more expensive than the free or $2.99 iTunes download, and may also require some customization to integrate with the user's system.

One distinct benefit of this kind of VoIP softphone, such as the Counterpath line of business softphones, is that they can function as customer relationship management (CRM) tools, whether on the desktop or as a mobile VoIP phone app.

Benefits of Mobile VoIP Phone Service

Some of the benefits of VoIP phone service through a free VoIP calling app (or an extension of home or business VoIP subscription plans) is that callers can bypass their cell carrier's minutes plans, roaming charges, and their frequently more expensive rates for domestic and international long distance.

For instance, callers using a VoIP app on their mobile phones can use WiFi access to ensure that they don't exceed their bandwidth allotments, thereby avoiding costly overage charges. VoIP apps also support anytime/anywhere calling, and aren't limited by arbitrary revenue enhancers such as nighttime and weekend minutes, and other restrictions such as:

  • Rollover minutes
  • Incoming call charges
  • Messaging limits
  • Mobile-to-mobile calling (verify with your mobile VoIP provider, some do treat in-network and out-of-network calls differently)

Callers could also consider eliminating their voice (or at least dropping to the carrier's lowest tier of voice service), relying instead on a combination of WiFi and 3G/4G network connections and VoIP phone service.

Many VoIP apps (including Line2 and JaxtrSMS) also offer unlimited texting to any text-capable phone on any carrier. Others such as Viber offer free in-network texting.

Free VoIP calling using a mobile VoIP phone app is also a way to access features that might not otherwise be available to mobile phone users, even with a smartphone. A VoIP app that is an extension of a residential or business subscription very often incorporates the same business-focused tools available at home or in the office, such as 3-way calling, call waiting, caller ID, and more. In addition to softphones that support free texting, apps such as Vippie offer video calls, group chat, instant messaging, and multimedia attachments.

So-called 'dumbphones' may also get to take advantage of the more rudimentary aspects of VoIP service (texting and calls) as long as they have even a limited form of Internet access, but features such as video chat or voicemail-to-email most likely won't be supported. Check with your providers to see what phones and operating systems they recognize.

Data transmission for VoIP calls is also typically faster than cellular data transmission. The digitized signal is broken into packets and each individual packet is optimally routed.

In a nutshell, mobile VoIP phone service can significantly reduce monthly billing costs to cell phone users while also offering features unavailable through traditional cell phone carriers.

Other Types of Mobile VoIP Phones

Less common and less flexible types of mobile VoIP phones are the VoIP phones intended for business use within a fairly limited area, such as a factory, plant, or campus:

  • DECT
  • VoWiFi

Cordless DECT 6.0 (Digital Enhanced Cordless Telecommunications) phones are essentially fancy, high-powered cordless phones on a 1.9 GHz frequency range, frequently supporting SIP protocols and used with wireless LANs and small office PBX systems. DECT phones require a base unit, but have an interference-free range of about 100 yards from the unit. Popular VoIP phone manufacturer Grandstream introduced its first VoIP cordless DECT phone in June of 2012.

A VoWiFi phone (Voice over WiFi) is an IP phone that is connected to the company's LAN or WAN, enabling the user to wander throughout the facility and be reached at one extension. Essentially a portable landline, VoWiFi phones are ideal for facilities or IT personnel who are frequently away from their offices or cubicles.