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Home : Community : Ask An Expert : Archive : August 2004   August 2004     Mobile Messaging Apps August Issue Roxanne "The Expert" Singleton I am getting ready for the Olympics. Sure I am a zillion miles and ten time zones away from all the action, but I will probably stay hooked in when I can via the web. I'll also be able to keep tabs on the action from the browser on my mobile phone, but what would really float my boat would be to receive push messages about events and results, and get images from the games sent to my phone rather than having to browse to them. While these types of services are still in the nascent stages here in The States, there are some promising services happening in other places around the world. There's quite a bit of buzz about the promise of mobile messaging in Athens, but it clear there's still plenty of opportunity to deliver applications that bring a global event into the hands of mobile users worldwide. And this brings us to this month's question: How can I develop innovative messaging applications? I sat down with Vinod Valloppillil, Sr. Technical Product Manager, Mobile Messaging, and talked with him about developing messaging apps. Since MMS is a general purpose messaging based transport for multimedia content, a wide variety of applications can and have been built using MMS including subscriber photo management, voting applications, dating, news delivery, etc. — basically any situation where an applications developer would like to send a subscriber something more than the text only experience they are limited to within SMS. According to Vinod, "MMS applications can be both one-way (for example, broadcast of news multimedia content to a large number of subscribers) or two-way (for example, subscribers sending pictures of themselves are part of a voting / "Idol" type campaign). Other applications can take advantage of the multimedia capability including pictures, video, and audio. For example, "electronic postcards" incorporating a picture of a birthday cake along with the appropriate culture/language/country-specific music. Some devices will also support form-based content so that a user can interact directly with a service by selecting radio buttons or check boxes rather than having to manually enter text to reply." What Do Operators Want? Typically operators prefer for developers to interface to their MMSC using the MM7 interface. Vinod explains, "MM7 is a SOAP-based interface that provides access to a wide variety of messaging primitives including message submission, revocation, delivery report requests, and read report requests. Developers can use standard SOAP libraries and/or MM7 specific SDK's — including one from Openwave — to begin developing these applications. The other benefit of the MM7 interface for operators, and end users is security. Sending messages via MM7 requires that the application have explicit authorization to send on the network, thus helping eliminate the risk of unsolicited messages." "Some operators also provide developer access to MMS functions using the MM3 interface. MM3 is meant to provide MMS-to-Internet-email connectivity and is typically used by handsets to send messages to users on the Internet. In some cases, operators provide bi-directional access to selected content developers. These developers can use the MM3 interface by submitting their content to the MMSC as a MIME-encoded SMTP submission. Both MIME and SMTP are well known, widely documented Internet standards. In contrast to an MM7 submission, MM3 tends to be less widely available and far less functional. Typically only basic message submission is supported in MM3 while none of the delivery confirmation features in MM7 is supported." What Can Go Wrong? When it comes to developing applications, Vinod warns developers to beware. "The classic mistakes in building MMS applications are similar to the ones in SMS: getting the subscriber experience wrong," he explains. "Regardless of the fancy multimedia capabilities on the handset, at the end of the day, the handset is still a very limiting device when it comes to subscriber interactive services." This means that your application must be built with several key notions in mind: Asynchronous. A common mistake is to map a "synchronous" request/response user model - for example the one found on WAP or on the wired Web - to the Asynchronous nature of MMS. Asynchronous MMS applications are typified by potentially long delays between subscriber requests for a piece of content and eventual delivery of that content to the subscriber. As a result, the application needs to be carefully factored to ensure a minimal number of network hops to service a subscriber's request. Limited text entry. At best MMS clients have access to the same text composition tools as SMS clients. Various client capabilities. Not all devices are created equal. Some clients have displays as large as 320x240 while others are limited to 101x80, and some devices will support delivery of video clips while others accept still images only. While operators' MMS Centers integrate transcoding technology to help match content to handset capabilities, it is worth profiling the devices you intend to reach and formatting your content appropriately. As we concluded the discussion, I asked Vinod if he had any final advice for developers. "Buy an MMS camera phone and play around with it for a while!" he encouraged. "Way too many of the apps ideas I've seen are folks somewhat blindly taking an app that worked on the Internet or on WAP and unnaturally mapping it to MMS. As many have noted, the best apps for a new medium are the ones which couldn't have happened on any other." Are you working on a messaging application? The Openwave Developer Network has tools you can use to help. Check out the MMS Library and MMS Quick Start. If you are developing messaging apps, I'd love to hear from you. We can feature your solution like we did this month with PocketThis (click here to read what they had to say). Drop me a line and let me know what you are up to. In the meantime, I hope you get a chance to see some of the Olympics and cheer for your favorite athletes! Roxanne has been working as an application developer for over 10 years. Her goal is to successfully write this column without having to join the marketing team or sit on the top floor with the execs. Roxy recently sold her vintage Motorola brick phone on eBay for $15. If you have a general question you'd like answered or just want us to know what's on your mind, let her know. Or, for more detailed or specific technical support questions, please visit ODN Developer Support.