So You Have a Network Connection. Now What?

by Adam Powers, Macrovision , TechOnline India - March 20, 2009

Take a quick look around, networking is everywhere " from the simplest FPGA to the billion-gate SoC " almost every chip touts support for Ethernet, WiFi, Bluetooth or some other form of network connection. As you start building your next project, consider the potential of leveraging the possibilities for the networking port. There is a whole world of new networking protocols tailored specifically for embedded devices. These protocols are part of a set of standards called Universal Plug and Play (UPnP) that allow devices to be easily used by consumers with virtually no setup or configuration.

Take a quick look around, networking is everywhere " from the simplest FPGA to the billion-gate SoC " almost every chip touts support for Ethernet, WiFi, Bluetooth or some other form of network connection. As you start building your next project, consider the potential of leveraging the possibilities for the networking port. There is a whole world of new networking protocols tailored specifically for embedded devices. These protocols are part of a set of standards called Universal Plug and Play (UPnP) that allow devices to be easily used by consumers with virtually no setup or configuration.

As most people are familiar with the convenience of the web, the most obvious decision might be to embed a webserver directly into the device to allow users to access the Internet. Sure, HTTP, HTML and JavaScript are great " they are widespread, well established and have solid community support " but they are not designed to be embedded in devices for the home. For example, without a personal DNS server setup in the home, users would have to set up static IP addresses and type them by hand into their browser in order to access the webserver. Traditional webservers also don't facilitate device-to-device communication.

UPnP solves these problems and makes networking in embedded devices particularly interesting and useful. The standard relies on a protocol called Simple Service Discovery Protocol (SSDP) that allows new devices to announce themselves on a network, or allows one device to search for another. SSDP enables one device to always find the other on the network regardless of their individual IP addresses. Once connected, the devices can expose a number of predefined and standardized services and "communicate" what functions they can perform over the network.

UPnP can also be embedded into a device using about the same amount of resources as a TCP/IP stack, not requiring addition of another 8MB of flash, memory to the design, or drain of processing cycles from the CPU. This will save resources for those working on a limited budget.

Embedded UPnP Services

Aside from the ability to automatically discover devices, there is much more that the UPnP standard can enable in a product. There are a number of standardized services, called Device Control Protocols (DCPs) that allow devices to do practically anything. Think of being able to store data without having any local storage. Think of having a User Interface (UI) without a local screen. Think of being able to share or playback virtually any kind of audio visual (AV) content from any device.

Some specific examples of UPnP services that use DCPs include:

Media Server and Media Renderer: This client-server set of services allows one device to store and serve AV content, and another to automatically recognize and play back that content.
Internet Gateway Device: This permits any device on the network to find the network gateway and automatically control firewall functionality, such as port forwarding, which is very useful for Internet-aware devices.
Printer: With WiFi and UPnP printer-enabled cameras and mobile phones, you can print directly from your camera or mobile phone to the printer.
Scheduled Recording: With this, any device can schedule a recording on a DVR via the network.
Lighting and HVAC: This provides all the functionality of X10, but over more modern networking connections and its easier to set up as well.
Remote UI: A UI can be sent from one device across the network to a second device. The second device can then control the first device from its own screen.

UPnP specifications can be found at: http://www.upnp.org

Currently the most popular type of UPnP service is the Internet Gateway Device service, which is built into almost every modern Internet Router and Wireless Access Point from companies such as Linksys, Netgear and D-Link.

Some of the more glamorous and perhaps the fastest growing UPnP services, are the Media Server and Media Renderer services, which serve as the foundation for a new generation of devices, such as home Network Attached Storage (NAS) and Digital Media Adapters (DMAs). Media servers are the combination of a storage device and network connection, allowing content to be saved, shared and played with VCR functionality. A media renderer enables the receipt of content that has been pushed by a controller device, which allow devices like the television to play music from an mp3 player or movies from a laptop in a standard way,, allowing the full glory of enjoying a complete media library whenever and wherever a consumer chooses. Devices like the Xbox 360 and Playstation are Digital Media Players (DMPs) that have UPnP built in, which allow them to control other devices and directly request content that to play back from a server.

All services are exposed by devices through XML service descriptions, which reveal Simple Object Access Protocol (SOAP) application programming interfaces (APIs) that other devices can call. This provides an extremely simple interface for embedded devices to control other devices " they can simply invoke a single SOAP action without any complicated enumeration or identification procedures. This allows for the most compact code and the easiest path to implementation and integration into larger applications. More sophisticated devices can even use UPnP's General Event Notification Architecture (GENA) to send and receive asynchronous updates.

Offering a unique product that distinguishes itself from the competition is especially critical in the consumer electronics business and this is where UPnP really shines. UPnP is a standard that can be easily extended, allowing for vendor-specific extensions at almost all levels of specifications. To top it off, UPnP is an open and free standard, allowing everyone to participate in the standardization process. Your proprietary service today could be a standard for the industry tomorrow, making it a very exciting time to be in the consumer electronics business.

A Place Where Everybody Knows Your Name: The UPnP Community

One of the most beneficial things about embedding UPnP into your device is that you will be in great company, which is the point of using a protocol like UPnP " having other devices that your system can talk to and share information with.

Some of the software and devices that currently have UPnP built into them include:

Windows Media Player 11
Xbox 360 and PlayStation 3
PCs and Laptops, such as Sony Vaio, NEC, Acer and others
TVs, such as the Samsung Series 7, Toshiba REGZA, Sony BRAVIA, Sharp AQUOS, HP MediaSmart, and others from JVC, Philips, Hitachi and Pioneer
Routers, Home Gateways and Wireless Access Points, such as those from Linksys, Netgear, D-Link and others
Sony CyberShot and Samsung TL34 cameras
Nokia N95, Samsung Omnia, and Sony Ericsson C905 cell phones
Many Blu-Ray players, such as those from Sony and Pioneer

To give you an idea of the pervasiveness of UPnP, ABI Research predicts that by 2012 there will be an installed base of 1.8 billion UPnP devices . Most of these devices implement the Media Server and/or Media Renderer services, especially since they are part of the Digital Living Network Alliance (DLNA) guidelines. The DLNA is a superset of UPnP that specifies how UPnP interoperates with other technologies, such as media formats and DRM protocols.

The DLNA, and in turn UPnP, has been adopted by standards such as CableLabs OCAP (now called tru2way), DVB-HN and ARIB ISDB-T. In short, you can expect to see UPnP in cable television set-top boxes (STBs) around the world in the very near future. This allows for a great touch-point for devices, since STBs are a familiar interface for entertainment and can serve as an interface for virtually any type of content. They also can make one of the most compelling types of entertainment " such as television " available to any other device.

The DLNA is also in the process of expanding the reach of UPnP into other standards and devices. The most recent release of the DLNA Guidelines, Version 1.5, standardized how mobile devices and printers can connect to networks and share content. In the future, expect to see standards from the DLNA around sharing content with cars, as well as providing enhanced television services such as sharing EPG metadata and streaming TV tuners over the network.

Connected Devices by Consumer Demand

All these device capabilities sound intuitive and exciting, but it is important to understand that these standards are truly aiming to solve real world problems for consumers. In an age where the average consumer seems to buy a new digital device every week, it is becoming increasingly difficult to manage all of these devices and the content residing on them. Consumers are frustrated with having to keep track of their digital media. Are the pictures from their vacation on the PC, still on their camera, or did they already back them up to their networked hard drive? Is that movie they downloaded still on the DVR or did they copy it to their portable video player? In a digital world users understandably feel like they shouldn't have to deal with these frustrations " they should be able to access their digital content anywhere, anytime and from any device.

As digital devices start to speak the same language, we can expect to see devices increasingly live up to customer demands and push frustrations to the side. The common language of UPnP and the standardization of content protection schemes and media formats in DLNA are facilitating the daunting process of a simple connection for all of the devices in your home.

The Choice is Yours

With this perspective under your belt, reconsider that network connection on your new SoC and bear in mind the possibilities of emerging home networking standards. Whether you are building a digital TV, an alarm system or an intelligent light switch, it is to your advantage to be part of the home networking community. Not only will you be able to go above and beyond your competition, but you will be making your end user's life a little bit easier.

Adam Powers is Director of Standards and Emerging Technology for Macrovision, and the Chair of the DLNA Ecosystem Committee. He can be reached for question or comment at apowers@macrovision.com.

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