This article originally appeared in the Dec. 2011 issue of INTERNET TELEPHONY.

Like peanut butter and chocolate, or cookies and milk, presence – typically in the form of colored jellybeans – has gone hand in hand with desktop instant messaging applications since the very beginning. For the last decade, users have been trained to know that a green-colored jellybean means that a user is available, while a red one means they are not. While there are variations in the colors and meanings across different clients, everyone – from Skype (News - Alert) to Windows Live Messenger to Google Talk have used these little colored jellybeans in very similar ways.

Clearly the telephone network – both landline and mobile – has gotten by without presence. Yet, traditional instant messaging apps have needed them from day one. Why is that? The reason has to do with the rate of user availability. On a landline or mobile phone, a caller can reach the user at any time (assuming their battery has not died or they are out of coverage). As such, callers have a high expectation that placing a call will ring the callee, and that sending a text will cause it to be delivered. In other words, users expect that the callee can technically be reached all of the time, and that a no-answer is because the human being is unavailable, not because the system is unavailable.

However, with desktop software, this is simply not true. Users are usually not in front of their desktop or laptop computers, and the software isn’t always running. In order to avoid user frustration, hints were needed to inform the user of the status of the callee. Online/offline indicates that the software is running. “Away” (also known is idle) looks at whether the user has recently used the keyboard or mouse, and therefore helps give the user an indication of whether the callee is in front of his or her computer.

Though presence has served the industry well for the last decade, much has changed since the days of desktop messaging apps. Mobility – through smartphones and tablets – has dramatically altered the ways users consume software. Modern mobile devices have four properties that change the way we need to think about presence:

·         They are usually with me. A desktop computer stays put. Even though laptops can move around, they are not always with a user. On the other hand, mobile phones are almost always with their users, and even tablets are more frequently with the user compared to laptops.

·         Push means the software always runs. Modern smartphones include push notification services that allow applications to send messages to users even when the software is not running on the phone. In essence, their software is always running – in the cloud.

·         Devices are always-on. Modern smartphones and tablets really never get powered off. They are always on, but may be in a low-power standby mode.

·         Full-screen: Mobile apps are full screen. This means that most of the time, users are not looking at the user interface for any particular application. They only look at the one with which they are interacting right now, and everything else is invisible.

These changes have a serious impact on presence. Because devices are always with the user, are always-on, and can always be reached through push, the notion of being “online” is not really meaningful. They are always online. In essence, the availability profile for real-time IP communications is on par with cellular and landline voice services. Similarly, because these devices are typically with the user all the time, the notion of “away” or “idle” isn’t meaningful either. Just because users are not interacting with the input modalities of the device does not mean they cannot be reached by software on the device. As such, “away” and “idle” are simply meaningless in a mobile world.

Perhaps most importantly, the usage profile for how users consume presence has changed. In the past, they would have a desktop app that was always running, and constantly receiving presence updates that were used to keep buddy list fresh. The constant in-flow of presence updates was not an issue when devices were always plugged in (or had large batteries), and where bandwidth was readily available. For mobile devices, where battery and mobile bandwidth are the most critical resources, constantly receiving presence updates is wasteful. Indeed, given that user’s will only look at their presence lists for the brief moment they are on-screen on a mobile device, constantly pushing presence in the background is truly a waste.

Does all of this mean presence is dead? Of course not! What it means is that presence needs to evolve, to be ready for the present. The notion of availability in the technical sense will fade away. Instead, other aspects of presence – device capability (does my phone support video calling) and user willingness (e.g., do-not-disturb) will become more important. Instead of presence systems being optimized around long-running subscriptions, they will evolve to be optimized around rapid queries to fill in bits of UI rendered on-screen. The red/green/yellow jellybeans will change, presenting users with more meaningful information for the task at hand.

Presence is here to stay. As milk is to cookies, so presence is to IP communications. It will just evolve to meet the needs of modern mobile computing.

Jonathan Rosenberg is chief technology strategist at Skype (www.skype.com).