I am implementing Bulk SMS in my application with the help of HTTP API's. Since HTTP urls have limit in number of characters to be sent at a time, i cannot request API along with all the numbers at once. So following is the logic i am using
Number of Phone Number : 10000
Number of Phone Numbers per Single HTTP API request : 100
A Queue to send 100 request and process 100 response. I am expecting something like "Tornado Queues" (http://www.tornadoweb.org/en/stable/queues.html)
You have a couple of options. Build your own queue using PHP but it will need some sort of DB backing like MySQL or Redis. I like Redis a lot because it is fast and doesn't cause additional load on my main DB. This is a good implementation of a queue using PHP. You will need the pcntl extension installed if you are going to directly use this example.
Otherwise you can use a 3rd party service that manages the queue and that you communicate with via webhooks.
This is a good resource for queue options in general and should extend your general knowledge.
Of the top of my head Beanstalkd, RabitMQ and IronMQ are popular solutions.