Group SMS – A Story About A Counter-Intuitive Solution

by Alon Cohen

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As you may know, anyone can create a group SMS on an iPhone by adding two or more participants to the “to” section. This method is also compatible when messaging Android smart phone users.  As a bonus for iPhone users, it even supports MMS (i.e. Pictures).

One problem with this method is that when you create a group, there is no way to save it in the phone address book. Also, if you include people that do not have a smart phone, they cannot respond to all nor can they create such a group either.

Prior to the iOS update that introduced the current group SMS functionality, users could send one SMS to a group of people.  The problem was that each recipient could only respond to the sender.  It was around that time that I sat in a restaurant with my son, Gal Cohen, (at the time, a computer science student at Rutgers University) and we tried to think of service ideas for Phone.com that might appeal to students.

We recognized that students primarily use SMS (Texting) for communicating with their friends and that hanging out together is a big portion of what occupies their minds.  With that realization we came up with the idea for an application that might help them communicate via SMS when they try to plan a night out. From this discussion emerged the Phone.com Group SMS service.  Our goal was to create a service that would work from any phone, smart or not, and provide the ability to create persistent groups that could be saved, invoked, created and managed!

The main obstacle we ran into is that in order for each group to be persistent, they need to have a phone number that is stored in the user’s address book. This is very costly since sooner or later Phone.com would end up with thousands of groups and a phone number associated with each group. Phone numbers in inventory represent a cost to the service provider (e.g., Phone.com) that holds them.

The solution that we found is counter-intuitive. Instead of allocating a phone number to each group, we decided to assign one to each group participant.  This must sound crazy considering I just said that numbers represent a cost.

Here’s how it works.  As long as we know the user based on their caller ID and we never assign the same user the same number twice, we can reuse telephone numbers between different users. In this case, the maximum number of phone numbers we will ever need is equal to the maximum number of groups our most social user will need. In other words, if our most social user has 100 groups, we will need 100 phone numbers for millions and millions of different groups. Our back-end obviously needs to be a bit smart in terms of managing the process, so for the sake of simplicity, I will leave that out and let you read about it in our GroupSMS patent!

I know it sounds a bit complicated and if you did not understand it, you are in good company! It took me hours of working with a patent lawyer to explain it in legal patent language and later elaborate on it to the patent examiner. Luckily, they eventually understood it. They realized this was an innovative solution and allowed our patent.

To try our app, download Group SMS from the App Store.

If you are on any other phone, you can use our free service by sending the text below to 1-973-577-6378.

The TEXT you will need to include in order to initiate a group SMS should be formatted like this:

PhoneNumber1 ParticipantName1 PhoneNumber2 ParticipantName2 PhoneNumber3 ParticipantName3 YourNameLast

Once the bridge responds, it will receive a Persistent Caller ID that you can save in your address book under something like “Group AlonPeterJeremy” or “Group Emergency.”   Give it whatever name you with and you are done.  Now, any time you wish to send an SMS to your group you can simply send an SMS to that particular contact in your address book.

If you text the word “Help” to 1-973-577-6378 you will get few more goodies to play with!

Enjoy! It’s free!

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