PrivacyStar Intelligent Mobile Call Management

Gerry Purdy J. Gerry Purdy, Ph.D.
Principal Analyst, Mobile and Wireless | LinkedIn

PrivacyStar Intelligent Mobile Call Management

Apps that eliminate unwanted calls are evolving to become an embedded service in the wireless operator’s network so that all subscribers can benefit from intelligent call management. PrivacyStar can recognize numbers used by telemarketers, debt collectors and political fundraising organizations and intercepts them so that customers are no longer bothered.

How many times have you received a call on your smartphone and had no idea who it was from? This happens when the party calling is not in your contact list. If the call is from someone you know and have in your contact list, the handset OS, such as Android or iOS, associates a name with the number.

If an incoming call simply shows a phone number, the call could still be from someone you know, but their number is not in your contact list. In this case, you see the number on the display, but not the caller’s name. Sometimes the number is not even known, like when the call is made over the internet using VoIP, and the smartphone displays “unknown.” So, you wonder, “Should I answer this call or not?”

Most of us answer these calls out of curiosity only to find that the caller is none other than a telemarketer or bill collector, or possibly a personal call from someone you do not want to talk with at that moment. In these instances, we’re often left wondering, “If I had only known the unknown before the call, I wouldn’t have picked it up!”

After receiving an unwanted call, many people know to immediately go into their smartphone system settings and add the number to the ‘block list.’ Then, whenever that number calls their phone, the phone will block it. Most mobile operating systems provide for that capability; however, the problem is not permanently fixed by doing this. The simple reason is that most telemarketing and bill collection companies use hundreds, and sometimes thousands, of numbers when they make outgoing calls.

For example, if the call is from a telemarketing firm, they know you answered the call. They tag your number as ‘answered’. So they schedule a second call to you a day or two later using a different number. The phone rings again with a number that is not in your blocked calls list or your contacts. Innocently, you answer the call again. Guess what? It’s from the same telemarketing firm that called you just a few days earlier. Now you have to go into system settings and block another number. You eventually realize that this is a hopeless cause; they stay ahead of your ability to block their calls.

At this point, you realize that you want to block all of the numbers from that company. Clearly, there is a huge problem with unidentified, unknown and unwanted callers.

Judging from the fore-mentioned scenario, it is obvious that a system that could manage unwanted calls would be in high demand. Fortunately, one company – PrivacyStar – has spent over six years working on this problem. The company now has a solution that helps both consumers and enterprise employees from receiving unwanted, or even subsequent, calls from undesirable parties.

Figure 1 shows the overall architecture of the PrivacyStar system. First, the incoming call is intercepted by PrivacyStar. From there, the call is identified as either OK or unwanted. Note that if a future call comes in from an unwanted caller, the PrivacyStar system blocks the call and the user never really sees anything happening.

How PrivacyStar works

PrivacyStar had two challenges as it set out to solve the problem of blocking unwanted calls:

  • Call Intercept The first major challenge was that PrivacyStar had to figure out how to intercept the incoming call. This required deep integration with the phone’s operating system, which used to be only possible with Android since the open source allowed PrivacyStar to modify the operating system code to enable call intercept. More recently, iOS 10 provides additional APIs that enable PrivacyStar to provide a similar service.
  • Unwanted Caller Database The second major challenge PrivacyStar had was to determine if the incoming call was unwanted. In order to solve this problem, PrivacyStar created a database of unwanted numbers. Then, if the call is in the database of unwanted calls, PrivacyStar can automatically block it. Over the years, this database has grown to include tens of thousands of unwanted call numbers.

PrivacyStar has been growing at a high rate with more than 500,000 new subscribers globally signing up for its service each month.

A summary of the way PrivacyStar works is shown in Figure 2.

PrivacyStar process

If the incoming call is from someone not on the restricted call list, the screen has a green color to indicate the call is likely okay. If the screen is yellow, there’s a caution about the call; if it is red, it is known to be an unwanted call.

The different PrivacyStar service options are shown in Figure 3. The system can:

  • Let the user mark a call as unwanted and block future calls
  • Provide more information on numbered calls (via reverse number lookup) and, thus, give the user more information about the source of a call
  • Identify scammers as well as all their phone numbers
  • Identify debt collectors and telemarketing firms as well as all their phone numbers
  • Give the user the ability to file a complaint with the FTC, which could result in a fine paid by the source of the unwanted call up to $1,500 per call
  • Allow the phone to be set as “Do Not Disturb”
  • Identify all calls made under a specific name

PrivacyStar services

The PrivacyStar system gives the subscriber an option to declare the call as unwanted. If it is unwanted, the subscriber declares what kind of unwanted call it is, e.g. from an unwanted personal call, telemarketing firm, bill collector, etc. This enables PrivacyStar to use its growing subscriber base of millions of users to help update the restricted call list via crowdsourcing. Each number that is flagged as unwanted is then analyzed to verify if it is from one of the companies in the restricted call database.

PrivacyStar now has more information on unwanted phone numbers than any other company in the world. In addition to simply blocking unwanted calls, PrivacyStar can also automatically file a complaint with the FTC that can generate a fine against the telemarketing firm up to $1,500 per call.

If you have an Android or iOS phone, you can sign up for the PrivacyStar service, which is sometimes branded by the wireless operator. It’s very affordable with its typical basic service averaging $1.95 per month. After subscribers initiate the PrivacyStar service, they typically say they will never give it up; and if they move to a new wireless operator, they will immediately sign up for the service again.

The PrivacyStar go-to-market strategy is shown in Figure 4. The company sells direct via the respective iOS and Android operating system, wireless operators and partners (white label distribution).

PrivacyStar go-to-market

PrivacyStar has been working with a number of wireless operators both in the US and Europe, and has made an investment of time and money to enable the PrivacyStar service to be offered by a wireless operator. In order to do this, the engineers at PrivacyStar had to interface directly with the internal signal detection and management system. The most popular call detector system is from the TITAN Centralized Signaling and Routing Control (CSRC) platform. This investment has finally paid off — the PrivacyStar system is now live on T-Mobile with other operators to follow. This is shown in Figure 5.

The operators that have not yet embedded the PrivacyStar system are
shown on the left. PrivacyStar goes to market through the operator, but the user accesses the service via a mobile app from either the Apple App Store or Google Play.

On the right, it shows where PrivacyStar has been embedded into the operator’s network. This enables the operator to go to market with its subscribers with convenience billing using either its own brand or the PrivacyStar brand.


PrivacyStar is one of the most successful startups in recent mobile history. It’s great to see that innovation is still flourishing with new concepts like PrivacyStar coming to the market. If you don’t have the PrivacyStar service on your smartphone today, odds are likely that you will in the very near future.


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