Mobile VoIP- Free Voice calling options

I was reading Markus analysis about different calling options and why one is better than the other. I thought of summarizing some of these options with more technical details. I kind of feel it’s geekier and may not appeal to all the audience. Still, I will try my best to appease all the audience.
Mobile VoIP is slowly coming out of the shell and becoming more disruptive. In its purest form, Voice call origination from a Mobile phone that uses IP as a backbone for traversing voice packets could be termed as Mobile VoIP. Here the assumption is Voice packets travel all the way to the handset through mobile IP backbone and not TDM backbone. Nevertheless, most of startups claim their solution as Mobile VoIP; there argument is- considering there are two legs in the call, even if one of the legs uses VoIP and the call is originated from Mobile, it is still considered Mobile VoIP. Well, either way we could argue why, and why not.

So here is different Voice calling option’s from a Mobile VoIP perspective, using which user’s can make Free/Cheap local and international voice calls. (I’ve put some pictures to explain each of these options. “A picture is worth a thousand words”) I have addressed advantages and disadvantages for each of these options. In Addition, it has some information on how users can save those hard earned penny when it comes to international calling; please read below.

Typical Mobile VoIP calling scenario-
Using his/her mobile phone, user could call a-
o mobile phone
o Landline number
o SIP client
o IM client’s like yahoo,skype,AOL,MSN etc
o International Number

Call through Model that uses Cellular Data network for voice packet traversal

Voice Calls originated from the handset uses operator’s Cellular data network. The soft client residing on the handset initiates a voice call using the standard SIP/XMPP or any other propriety protocol. Here the originating side of the call uses data interface (GPRS, EDGE, 3G, HSDPA, WIFI etc). There is definitely a voice quality issue depending on the data speed supported by the operator broadband network. Hopefully, the latest 4G or WIMAX shall address mobile bandwidth issues. In case of a Dual mode handset, WIFI network shall be used to originate the voice call. Depending on the terminating user type, for e.g., if it’s a mobile or landline number, then the call is routed through a circuit switch network. So the user pays only for one leg of the call. If the call is terminated to an IM client or SIP client, user doesn’t have to pay anything. It’s free Voice Call.

Advantages:
o In case of call termination to IM clients like Skype, Yahoo, MSN, AOL etc, user has the flexibility to reach his IM buddies from mobile phone, which was possible only with a PC environment.
o In case of calling a mobile or landline number, pay only for one leg of the call. The originating leg that connects to the third-party gateway server is completely free, as it uses Cellular Data Networks. Off course, user has to pay for the mobile data package.
o Receive all incoming call from IM clients like Skype, Yahoo, MSN, AOL etc, from your mobile phone. Freedom from PC!

Disadvantages:
o Good Voice quality may depend on the mobile broadband supported by the operator. In case of GPRS, voice quality will be pretty bad. Nevertheless, with the latest advent of EVDO-REVA, HSPA,WIMAX or 4G, this shouldn’t be a concern anymore
o You need a have unlimited Mobile data package
o Soft client may not be available for all the handset models. Limited only too few handset models.

Startups that follow above calling models are: Fring, Truphone, Barablu, Mig33


Call through Model using operator’s circuit switch network

Voice Call originated from handset uses TDM resource to connect third-party vendor’s gateway, which in turn connects the called party using IP or TDM interface, depending on whom the caller is trying to reach. A predefined gateway number is configured with the handset client for voice call. Whenever a voice call is initiated from the handset, soft client initiates a voice call to the gateway number. In addition, an SMS or IP transport is used to exchange signaling (information about contact or group) messages with the Gateway. Most of the mobile VOIM (iskoot, eqo) products use this kind of signaling methods to convey contact or group information to the gateway.
Mobivox also uses Operators circuit switch network to connect the originating calls. However, in order to use their service, you don’t need to download any soft client on the handset. This makes them sexier than other startups in this space. When you register with Mobivox, a dial able number is assigned to your mobile. Any calls to this number shall connect you with VoxGirl, which will guide you with the call.

Startups that follow above calling models are- Nimbuzz, Iskoot , Eqo, Mobivox

Advantages:
o No Unlimited Mobile Data package required.
o Use your existing cellular minutes to call your IM buddies all over the world. If you have an unlimited voice calling plan, you could call any of your IM buddies across the world free of cost.

Disadvantages:
o Need call forwarding for receiving calls from your IM buddies across the world. So for e.g., if you want to receive call on your mobile from your Skype buddy residing in a different country; you need to buy Skype in credits to support this option.
o In case of calling landline or mobile calling, user shall be charged twice the rate. This is because the callee and the caller are connected by the third party gateway.
o Availability of local dial-able gateway number.


Call Back model, using the Mobile Web or SMS

Using the mobile web interface, user can enter his/her number and his/her friend’s number. Within some seconds, user would get an incoming call from the third-party gateway, which will bridge the call between him and the friend. This makes more sense when making a long distance or international calling. What you end up paying is a local airtime fee, if the other end is a VOIP endpoint or fewer rates for international calling, because of VoIP backhaul being involved in call setup. Another interesting call back model is- sending an SMS message with callee and caller details to the third-party gateway. Based on the SMS message, the third-party gateway shall bridge both the numbers. Raketu RakSMS is an example of this model.

Advantages:
o No need to install any third-party clients.( Mobivox)
o Works on pretty much every handset in the world

Disadvantages:
o Mobile-to-Mobile or Mobile-to-Landline are charged twice the rate since both callee and caller are connected through the third-party gateway.

Startups to watch: Jajah, Talkster , Gizmo

BTW, i got a mail from jajah mentioning about valentines deal from jajahdirect.
check out the link- Jajah valentines day deal

Looking at all these different options, it would be great if one of these startups can come up an intelligent soft client that can decide the calling option based on location, data coverage, availability of local number and international roaming. My point is- User doesn’t have to understand all these complicated calling models. Bottom line, cost effective calling and good voice quality is what user cares than how these complex technology works. Is somebody listening!