RFID Enabled Middleware For Wide Area Gaming

BRINGING THE SPECIFICS INTO LOCATION

Overview

Area: Wide area gaming is a strand of gaming that has great potential but is hampered by existing technology and standards.

Our approach: This project seeks to solve this by utilising can RFID in gaming and other wide area applications as the location determining technology.

Tools at present: GPS is the most commonly used technology in this area but it has some serious limitations especially in urban areas where this type of gaming is most popular.

Determining Location

1. GPS (Global Positioning System), is able to show ones position on the Earth. GPS satellites, 24 in all, orbit at 11,000 nautical miles above the Earth. They are continuously monitored by ground stations located worldwide.

Pro: No need for network infrastructure, cheap receiversCon: High buildings, need line of sight2. Cellular Triangulation is a process by which

the location of a radio transmitter can be determined by measuring either the radial distance, or the direction, of the received signal from 2 or 3 different points. The distance is determined by measuring the relative time delays in the signal from the mobile set to 3 different base stations.

Pro: Technology in existence, we all have phonesCon: Coarse readings, pricey, reflection of signals

Wide Area GamingWide Area Gaming is a branch of computer games where the real world location of the players and actual geography of an area

becomes elements in the game. Wide area gamers have harnessed the power of GPS, high-

resolution screens of handheld computers, cameras and the latest mobile phones to play

games across towns and cities, where they become spies, vampire slayers and even Pac-

Man.

These technologies allow the players to track the path taken by them and their friends through an area. This means that these games can now be tied to location, bringing together communities of gamers or setting them against each other in treasure hunt games that unfold in the real world. These wide area games can take many forms but as a rule, they take place outdoors and on a much larger scale than normal computer games.

WAG ExamplesGPS Tron based on the 1980’s classic arcade game Tron. In the original Tron the object is to surround the computer's yellow cycle with a trail of light emitted from the back of Tron’s blue cycle. If the players’ cycle runs into the side walls or light from any of the other cycles, he dies. In the new wide area game, GPS Tron, players drive around in their cars with GPS enabled mobile phones leaving virtual trails

Pacmanhattan is an wide area game played in New York, which recreate the 1980’s arcade game Pacman. Players play the parts of Pacman and the ghosts with the Pacman player running around the streets trying to gather all the virtual dots while trying to avoid the players playing the ghosts. The system uses mobile phones, WiFi connections and some custom software

WAG ExamplesMonopoly Live was a game launched by Hasbro where the 18 London taxis with GPS tracking devices and tracked them over the internet. Online players could pick their taxi driver, pick the properties you want to own and watch as the taxis drive around London hoping that they will land on your property. Monopolylive.com let you play Monopoly in the real London with 18 real cabs fitted with GPS systems as your movers

Uncle Roy All Around You developed at the University of Nottingham, UK, as part of a European effort called the Integrated Project on Pervasive Gaming. A player has just an hour to find the eponymous Uncle Roy by following instructions or clues fed to him via cellphone text messages. But every time he moves, the positioning technology on his phone transmits his exact location onto a virtual map of London, allowing other players in the game to track his movements and hunt him down. Meanwhile a small band of performance artists called Blast Theory shadow the player like spies manipulating him in his quest to find Uncle Roy.

RFID

An RFID system consists of two parts, a transponder/ tag and a reader. A typical RFID tag consists of an integrated circuit (IC) connected to an antenna and mounted on a silicon substrate. The IC stores the unique serial number of the tag and may have extra memory. Tag memory can vary greatly from one-bit tags to the 64 kilobyte tags used by Boeing & Airbus

Tags are packaged in a number of different ways depending on their planned application. They can be embedded in to adhesive labels that can then be printed – called smart labels, embedded in to car keys and plastic cards for access control and they can also housed in glass cases to be injected under the skin of humans and animals.

RFID can trace its roots back to the 1930’s when many countries were trying to solve the problem of identifying aircraft as friends or foe. Before the advent of radar technology, distinctive colours and markings identified planes however radar showed only a featureless dot on the screen. The solution to this problem was termed IFF, which means, “Identify friend or foe” and was invented by the British in 1939. A transponder was placed on every plane and when the transponder received a signal of a certain frequency from ground based radar stations it would then send back a signal of the same frequency with greater amplitude, which identified it as a friendly plane (later becoming the basis of air traffic control systems worldwide.)

RFID TagsThere are two broad categories of RFID tags defined by the source of their power, passive and active. Passive tags are the most popular tags in use today as they are substantially cheaper to produce than active tags.

An active RFID tag being installed on an ISO shipping container. The tags are programmed with commodity data for the container contents. By using the handheld readers companies can quickly and easily locate the equipment they

require.

Active Tags have their own power source, typically a battery, which is used to power the IC and transmit the tags data without the need for a reader. This allows for much larger read ranges than passive tags, usually around 30 metres but this can be boosted to 100 metres using specialised antennas

A passive tag does not contain a power source and draws its power from the electromagnetic energy emitted by the reader, which induces a current in the tags antenna and transmits the data stored in the tag back to the reader. Passive tags typically only have a read range of only a few centimetres.

RFID Tags

Here we see an RFID sticker that can be affixed to patients to help verify what they are there for.  The patient’s name and site of surgery are digitally encoded on the card, and readers decode the information.  Rather than simply ask, “Where should I cut you?” patients are then asked to verify the information on the chip.  Imagine the hacking potential here….

Other kinds of tags are semi-passive and chipless. Semi-passive tags use a built in battery to power the onboard IC but still uses the readers’ energy to transmit. Chipless tags which do not contain an IC or memory and the id of the tag is encoded by the unique patterns of materials that reflect back the readers signal. As they do not have an IC, they do not require the extra energy standard passive tag do so have a greater read range and are cheaper to produce.

Other characteristics of RFID tags are the memory type. Read-only tags have the data written at the time of manufacture and it cannot be changed. This essentially makes them tamperproof. Chipless tags would fall in this category. Write-once read many tags have the tamperproof benefit but with the added ability to write data to the tag once after manufacture. Read/Write tags as the name suggests can be written to as well as read

RFID ReadersReaders send out pulses of radio energy that power the tag and then listens for the response from the tag. Even though they are referred to as readers, many of them are capable of also writing to the tags.

The RF signal of the reader can contain a number of different commands for the tag, including a request to read different portions of the memory and requests to write to the tags memory. The reader is also capable of communicating the information it has gathered to a computer over a serial, Ethernet or wireless connection.

The RFID reader and tag can communicate using a number of different frequencies and currently most RFID systems use unlicensed spectrum. The most common frequencies that RFID systems use are low frequency (125 KHz), High Frequency (13.56 MHz), Ultra High Frequency (860 – 960 MHz) and Microwave Frequency (2.4 GHz). In the past most RFID readers were only able to read tags of a single frequency but multimode readers that are capable of reading tags of different frequencies are becoming cheaper and more popular.

The distance over which the reader and tag can communicate is called the read field. The size of the read field is determined by the antennae on both the reader and tag, the frequency used and the power of the reader.

Aha… I think I get it……(But to be sure, I’ll just sit here and look intelligent…)

So to recap……computer games and board games all have there own

fans but how about using a whole city as your game board. That is what many people around the world are doing. Some are playing life sized Pacman on city streets and others are solving a trail of clues to find a hidden treasure. It is a phenomenon that is known variously as Urban

gaming, Wide area gaming or location based gaming. It has been around since the 1990’s but it has not made it to the mainstream

mainly due to limitations & cost of the technology.

However, with Wi-Fi becoming embedded in almost every portable device urban gaming is on the cusp of making it big.

Radio frequency identification, however allows the identification of a tagged object through the unique serial number it transmits. It is part

of a broad range of automatic identification technologies.

By bringing these two technologies together, it is hoped that a Wide area game can be developed without the limitations of

the currently used technology.

UU Engineering to the Rescue….

We are currently refining the middleware architecture at the moment and we have just finished prototype 1 – wireless X & O’s.

The rest of the talk describes the components of this prototype. 1. the Client game which runs on the mobile device providing the user with a graphical interface. 2. The class which interacts with the Compact Flash RFID reader allowing the game to control it. 3. The database that stores information about each player and the state of play in each game. 4. The web service that facilitates communication between the client application and the database over the network, be it wired or wireless.

If we build it, they will come……

Therefore in collaboration with Meedja Ltd (A Dundalk based Gaming company), we have received funding under the InterTradeIreland FUSION scheme to create a Wide Area Gaming Middleware which utilises RFID as the location determining technology.

1. The ClientThe game was designed to be calibrated by the player so any tag could be placed in any position in the grid prior to beginning of the game and the game would then be taught the positions of the tags. This is because the RFID tags are visually identical to each other with no distinguishing markings. The user is given visual indication as to which tag to scan and informed when a successful read of the tag has taken place/ Error checking is done here to ensure nine distinct tags have been read. If the same tag id is read more than once the user will be prompted that this has occurred.

When all nine tags have been scanned the client then sends the tag ids to the web service which returns to the client a player id. If the web service cannot be contacted an error message is presented to the user which allows them to try to connect again.

Calibration of Game Setting Up the Board

2. Web ServiceThe web service provides the client application with a number of operations as explained below. The SetTagLocations operation is used in the setup of the game where the client sends the list of tag ids and their associated locations to the web service. This operation then writes this data to the database to the corresponding fields and returns to the client their player number.

The GetTagLocFromTagID operation performs a lookup of the database to determine the actual grid location of tag from a tag id supplied by the client application.

ResetDB clears the information of the last game played from the database to allow a new game to be played.

The WaitForTurn operation, when called by the client, causes the client to wait until the other player has successfully scanned a tag. This is done by performing lookups of the lastTagID field of the table tbltags. The lastTagID field contains the id of the last tag to be successfully scanned by either client and this corresponds to the last move made in the game. By monitoring this field until it has been changed by the other player the client will essentially wait for its turn.

3. The Database

The database consists of two tables called tblplayers and tbltags. Tblplayers contains information about the players who are playing the game including the IP address of the client and the player id assigned to client by the game. Tbltags contains information about the tags on the players’ board including the tag id, its location on the board and the player to which the tag belongs.

Tables of the Game Database Schema Contents of tbltags

Prototype in Action

A short Video Clip of the Prototype will be shown here

Conclusion

….Being involved in Urban Gaming is not all about GPS and Cellular Triangulation

…Being involved with RFID is not all about supply Chain ZZZzzzzzzz

…..No, sometimes the worlds can collide such as here

X & O’s is not the end…. No, the goal is the creation of a Middleware which allows heterogeneous mobile/RFID devices to plug and play with ease using our architecture

Special Big Thanks to:

Derek Harkin, BEng final year & Ian Tierney, Meedja Ltd