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Making Money via Mobile Devices [ 150 ] Using SMS in Mobile Payment Almost all the wallpaper and ringtone providers are running on Premium SMS-based payments. Even the votes we cast using SMS on a television contest are charged higher than normal. The following gure illustrates how SMS can be used to place an order. There are a few important aspects of this ow. POTR will advertise pizzas in newspapers, television, or any other media. Along with product information, we will also put up a code. To order, the customer has to send a message to a special number (called the Short Code) with a message in a specic format. The Short Code may be shared by many service providers, and hence the message may contain a keyword that will determine that it's meant for POTR. Along with the keyword, it will also have order information. The item code and quantity in our case. The network operator will deliver the message to the SMS Gateway, or Short Code Service Provider. The SMS Gateway will make an HTTP GET/POST request to POTR and pass on the entire message, along with the sender information. POTR can now process the order the way it wants. In our case, Luigi'll call back and conrm the order and take the address of the customer! • • • • • • • Chapter 8 [ 151 ] The customer is charged a premium fee for sending the message. POTR gets charged for SMS Gateway services and short code provisioning. POTR also takes care of order fulllment. The customer will get a hot pizza in the next half an hour! Let's look closer at two components of this ow: Receiving Messages and Short Codes. Receiving Text Messages We have seen how we can send messages using an SMS Gateway in Chapter 6. The process is as simple as making an HTTP request to the gateway-provided URL with certain parameters. But when we want to receive text messages, the job gets a little complicated. To receive messages, we need a number that people can send messages to and then, a system that will receive and read messages sent to that number. The nal step in the process is to forward the message to our application via an HTTP request. The critical part in this process is the number that people can send messages to. We need to buy such a number from the SMS gateway and pay a monthly fee to keep it alive. Such a number will normally be the full 12 to 16 digit mobile number. Some services can also use a "tagged number". A tagged number is an actual mobile number with some additional digits added at the end. All messages sent to the actual mobile number, irrespective of the tagged digits, will come to that number. The gateway can then route the message to the appropriate account based on the tagged numbers we have purchased. But Luigi thinks this number is too long! And he wants to get a Short Code! Getting a Short Code A short code is like a domain name—an easy-to-remember number that will be used to access applications online. Luigi, like many others, wants to map the short code to POTR—and wants to buy 7687 as his short code. A short code is constant across all network operators in the region (typically a continent). So all mobile users can send a message to the same short code and we will be able to receive them. The process of getting a short code can be time consuming—Clickatell takes up to 90 days. For the US and the UK, you can register short codes from http://www.usshortcodes.com (US) or http://www.short-codes.com (UK). Other countries have their own process of acquiring a short code. • • Making Money via Mobile Devices [ 152 ] Even short codes have two types: Random or Vanity. Vanity short codes are easier-to-remember codes that are sold at a premium price. Random short codes are random 4-6 digit numbers. The charges for both random or vanity short codes vary for different continents. Assuming we have got the 7687 short code for POTR, let us see how we can receive messages to it! Not all SMS gateways offer such a two-way messaging facility, but Clickatell has it. So let's get going! Receiving Messages via Clickatell 1. The rst step is to activate two-way messaging on our account. We then buy the short code and wait for it to function. In the meanwhile, we can go ahead and do our integration code. Refer to http://www.clickatell.com/ products/two_way.php for more details on two-way messaging activation with Clickatell. 2. To receive messages via HTTP, we must set up a callback URL with our API. We set this up from our Clickatell Central account. 3. Our callback URL will point to receiveMessage.inc.php—a new le we are creating. In the le, we rst validate incoming parameters from Clickatell. Let's see how this bit looks in the le. <?php // Clickatell sends us following parameters $from = $_REQUEST['from']; $to = $_REQUEST['to']; $timestamp = $_REQUEST['timestamp']; $text = $_REQUEST['text']; if ($from == "" || $to == "" || $timestamp == "" || $text == "") { echo "<p>Invalid parameters.</p>"; return; } ?> 4. We can now split the text into order parameters then loop over them and add items to the order. The following code shows the structure of this part, added right after the previous code. // Process the message here // Message format is "POTR (Item Code)x(Qty)" // Push a space around x so that we can split at space later $text = str_replace('x', ' x ', $text); // Convert all double spaces into single spaces while(ereg(' ', $text)) Chapter 8 [ 153 ] { $text = str_replace(' ', ' ', $text); } $text = strtoupper(trim($text)); // Now we can split at space to get order parameters $params = explode(' ', $text); $identifier = array_shift($params); if ($identifier != 'POTR') { echo "<p>Invalid command.!</p>"; } for($i = 0; $i < count($params); $i = $i + 3) { $itemCode = $params[$i]; $qty = $params[$i+2]; // Validate the itemCode and qty here // Add to order } // Save the order and notify customer 5. We now have a basic structure ready for processing incoming messages! We do not need to show any output here, because the request will come from Clickatell. Sending Messages That Can Be Replied To Clickatell needs an additional parameter while sending messages to make sure they can be replied to. This parameter is called "MO" (Mobile Originated) and the value for that must be 1. When we pass this parameter, Clickatell will set the number in the "from" parameter as the one that users can reply to. It will also try to route the message through an appropriate network operator. When the user replies to the message, Clickatell can pick it up and route it to our application. This completes the two-way messaging for us! So far, we have seen many advanced methods of receiving payments via mobile devices. But some payment gateways make it absolutely easy to get payments via SMS! Just send an SMS like "send 5 to orders@potr.com"! Sounds interesting? Let's nd out more! Making Money via Mobile Devices [ 154 ] Making it Easier—Payment Gateways Help get More Money! We mentioned that you have a good choice of mobile payment gateways. Many of these gateways support more than one method to get mobile payments. For example, Obopay (among others) makes it absolutely easy to send money to someone. You can send an SMS to 62729 (in the US) like "send 6505551212 17.95 Pepperoni Pizza plus Coke" (see the following gure). The money will then be sent to the user with mobile phone number 6505551212. If the owner of that number does not have an Obopay account, she or he will get an SMS notication and can sign up to receive money. Obopay allows payments via WAP, and also special software that you can download and install on your phone. PayPal too has a "Text 2 Buy" service that allows sending money with a simple message. Bango on the other hand, specializes in digital goods under $10. It covers a lot of regions of the world. And it also complies to Payforit (http://www.short-codes. com/payforit/)—a payment service supported by all UK mobile network operators. Bango also provides extensive reports and search integration. Chapter 8 [ 155 ] Different mobile payment gateways may offer different features. But the cost is also a major factor to consider. Consider all the costs involved when you decide on the payment gateway—including short code charges. We now have a good foundation in mobile payment. Let's review what we learned in this chapter. Summary In this chapter, we learned to receive payments and messages via devices. Specically we looked at: Using SetMobileCheckout and DoMobileCheckoutPayment for payment through PayPal Premium SMS, Credit Card, Proximity Payments, and other methods of Mobile Payment, their pros and cons An overview of security concerns in Mobile Payments Receiving Text Messages via Clickatell The usage of short codes and how to obtain one Luigi now wants an automated system to process orders coming via phone: an interactive voice response system that can give order status updates to customers and even take orders! Let's do some talking in the next chapter then! • • • • • [...]... Callers 1 Using voice recording software (such as Sound Recorder on Windows), create a short welcome greeting Save the file in 8bit, 8kHz u-law format as welcome.wav Most servers will play back audio in this format, even if you save it in higher quality, so it's best to save in 8/ 8 format at the beginning We have recorded Luigi's voice and saved the file! [ 162 ] Chapter 9 2 Voxeo applications are stored... with our chef, we need to call our 1 -80 0 number and transfer the line VXML has a simple tag for this: You can specify the destination number and protocol in it, and the server will automatically call that number, and bridge the lines when connected So this could be the code to connect our caller to our chef: ... keep things modular and flexible Keep a Watch on Your Syntax Make sure you make your VXML and grXML files in correct syntax Wrong syntax is the cause of major development problems in voice applications As a test, you can open the XML file with a web browser and verify that all tags are nested correctly If you still have problems, check the messages in the Log Viewer [ 166 ] Chapter 9 The code... input We have got a taste of voice applications, now Let's start writing our own Pizza Ordering application! Designing the Call Flow of Our Application Just as we need to take care of usability in our mobile web applications, we need to take care of it in our voice applications as well—in fact, more so in a voice application Customers do not like to talk to machines, and when they do, they simply want... cond="option == 'zero'"/> Please wait while I connect you to our chef Sorry, looks like chef is busy talking to someone else Umm... It uses SIP protocol to make calls to the Prophecy server Prophecy's services are waiting for a call Once the call comes in, they look up the location of the file that handles the call—just like how a web server would process a request The file is loaded, processed, and audio output delivered to the caller Examining the Log Viewer will tell you a lot about the internals, how different parts of the Prophecy... potr 3 Copy the welcome.wav file to the potr folder we just created 4 Create a new text file in this folder Name it index.xml, and enter the following code in the file Welcome to Pizza On The Run ... document level, providing a common fallback for any problems—we will do just that! Now that we have grasped these concepts, let us review our complete index.xml file [ 167 ] Interactive Voice Welcome... user input via the grammar We have already added a tag to the tag, so let us create a new file called dtmf_grammar.xml with the following code: assign(digit $return)... up on you I hope the call went well! Thank you for taking time to speak to our chef I think he liked your call [ 1 68 ] Chapter 9 I did not hear anything Please try again. Sorry, I did not understand that. . Save the le in 8bit, 8kHz u-law format as welcome.wav. Most servers will play back audio in this format, even if you save it in higher quality, so it's best to save in 8/ 8 format at the. DoMobileCheckoutPayment for payment through PayPal Premium SMS, Credit Card, Proximity Payments, and other methods of Mobile Payment, their pros and cons An overview of security concerns in Mobile. (http://www.short-codes. com/payforit/)—a payment service supported by all UK mobile network operators. Bango also provides extensive reports and search integration. Chapter 8 [ 155 ] Different mobile payment gateways may offer different