Smartphones, 4G, IP, and IMS – Part II: Why is this G like no previous G

Making a phone call is an activity that seems almost as natural as walking, or drinking, but it has a history. About 120 years ago the layout of the phone terminal, with transducers for speaking and listening, was a settled matter of design. In another 20 years the matter of dialing phone numbers was settled as automatic electromechanical telephone exchanges were introduced. A phone call is a blend of humans making accommodations to machines and machines being designed for humans, and much of the early outcome of that blending persists today.

If you look at the software in any mobile phone, the key thing that makes it a phone is the call-state management. This is what keeps track of the state of phone calls (and, in 2.5G and 3G, data connections, too). It enables the user interface of the phone to display the correct state visually and play the right call progress tones (the ones that originate in the handset) at the right time. It also hooks into power management to light the LCD backlight at the right times, the switch that detects if a flip phone is closed, the keyboard lock, and performs other operations that create the user experience of a telephone.

The design of all mobile call state management is based on having one bearer channel to a circuit switch, plus SMS and data. The first implementations of mobile call state management had minimalist requirements: Display the on-hook dialed phone number on a numeric display, play call progress tones the user would find familiar from the landline user experience, and enable control over a small set of switch-based functions like call-waiting, where the call on the single radio channel to the phone is switched to a second call. It is familiar enough to be accepted by customers and accommodating enough to the way the network works to be efficiently deployed.

There are some differences between CDMA, GSM, iDEN, etc. but they are close enough to share a lot of the implementation. 2G, 2.5G, and 3G differ in the richness of the circuit switched signaling (but not so much that users are aware of it), and in whether and how much data you have. GSM and UMTS/WCDMA data and HSPA differ from CDMA data in detail, but, again, there's not much user awareness of the differences. Color LCD displays on phones make text messaging nicer, but the impact on the mobile phone call user experience has been limited to presenting a contact list and call log.

4G is the first fundamental break from the roughly 25 year old model of cellular mobile telephony. In 4G, the radio is part of a network interface on an IP network, like a WiFi radio. There are no bearer channels dedicated to voice calls. You either do IP telephony using SIP, in the IMS case, or you simulate circuit switched telephony on top of IP in the VoLGA case. There is no practical limit to the number of voice calls and other kinds of communication sessions a 4G device can juggle. Packets traversing the carrier's network carrying voice to other endpoints are no different from packets flowing between the endpoint and a third party or private gateway/switch with a telephone network interface. Identity, communications services, media (how voice or video is encoded), etc., all become decoupled from the network.

So we are entering a product development phase where the winners will be, in part, determined by how well they can make compelling new communications features and capabilities based on this change without confusing the end-user. What it means to be a phone is now infinitely malleable.

Surely, at the bottom of this a phone call has the same limitations as a face to face conversation plus the further limitations of not being actually face to face. No, even this can be called into question. The ability to redefine the phone call experience is comprehensive and the potential is limitless. And the potential ranges from the obvious – what the user sees on a screen – down to the subtlest microsecond-level manipulation of the human voice.

But will this potential be realized? That is more in doubt than that the potential exists. So far, the modern general purpose pocket-sized telecomputer surfs the Web and plays games. It will take the realization that new communications products can be created, and sold, to motivate reconsideration of how phones enable communication.

Smartphones, 4G, IP, and IMS – Part I: Toward a Fully Mobile Enterprise Communications System

I have not been blogging much lately, and I plan to change that. I am going to do that by writing a series of shorter blog entries.

There are four big forces for change in the mobile market now:

1. Smartphones have broken out of the PIM-oriented business niche
2. 4G networks, WiMAX and LTE, are coming to market
3. IP voice has taken over enterprise telephony
4. The ideas of IMS, if not implementations of IMS, are permeating new communications products

My next several blog entries will look at the interplay between these forces and the opportunities they open up: 4G, with or without full implementations of IMS, mixing IP communication with mobile communication, the way business communication systems are, finally, co-evolving with mobile communication, etc.

The reason I will be focusing on the interaction between these forces is that this is where new opportunities are created, and new entry portals into existing markets with entrenched vendors open up.

For example, most people think of VoIP phones in two distinct ways: VoIP applications for smartphones, which are mainly used for international toll-bypass, and VoIP desk phones for businesses.

What's the problem here? In each case, these products have reached some natural limitations: Mobile VoIP as toll bypass has hit an upper bound on value – it's not much more valuable than a calling card. And VoIP business phones are becoming the second phone – the place where you get cold calls, the thing you leave on do-not-disturb, the back-up.

Can we find a way out of these limitations in the four forces that are driving change? Let's see how each affects a possible solution:

1. The new smartphones and smartphone software platforms enable richer and more integrated mobile VoIP solutions than the crude Java ME (J2ME) applications for mobile VoIP. You can transform the handset into a mobile enterprise phone, and directly replace desk phones.
2. 4G networks enable enterprise communication to become an over-the-top (OTT) service. There is no longer any difference between being on-premises and off-premises.
3. Now that you can extend IP communication to users on the go, there is no longer a need for crude “two stage dialing” to “log in” to a PBX while you are on the go. It's an all-IP world.
4. An IP-PBX being used like an OTT telephone service is IMS-like in many of the features it delivers, but does not depend on IMS in the mobile network.

This is one kind of innovation made possible by the combination of these Four Forces. In future posts, I will explore more basic innovations, and the details of some of these innovations.