Online Cab booking application design

I want to design a online cab booking application and i need your input to use best OO analysis design and design patterns(Observer/Decorator etc.)

1. A customer logged in Cab booking portal (CBS) and place the request for a cab.<br>
2. Cab request and Customer details store in Cab & Booking DB, where it log a new booking request to Cab Management Service CMS with details.
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3. CMS run the Cab Allocation Algorithm and track GPS Navigation System to identify cabs located for particular area of the city. And revert the available Cabs and Driver details to Cab & Booking DB.
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4.  Cab & Booking DB propagate message to Cab Message Service which further send message SMS to particular Cab Drivers for New Cab Request.
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5. Let a random cab Cab3 conformed the request and looged in Cab Driver System (An application (mobile) for Drivers) and send acceptance for Cab to the Cab & Booking DB. 
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6. Cab Message Service acknowledge the Customer with Cab and Driver Details.
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7. Customer boards in to the Cab3 and payment proceeds after journey. Cab driver print the invoice and invoice details sent to the Cab Driver Application

I want to know what are the classes and interfaces can be design and which Design Patters will be best for this problem statement.