Ricardo Reyes' answer covered (https://mcmap.net/q/1284879/-is-the-smpp-binary-sms-protocol-dead-closed) this question almost completely. Just adding my own experience in this matter.
Comment on binary messages
I work for a company that runs SMPP hub. We do handle business logic that handles binary SMS. The percentage is low, but they exist. Smartphones (iPhone, for example) can create binary SMS for long messages. We are seeing some use-cases.
Comment on SMPP spec
It is has been quite a few years that the SMPP spec has been updated. I have not seen any major carrier in the US to support SMPP 5.0 spec. Almost everywhere, it's SMPP v3.4. For me, the reasons are:
- SMPP v3.4 meets most requirement. Companies have found their ways around the
limitations.
- The growth trend for SMS is flattening. It may not make sense to spend resources on this area. Even though SMPP v5.0 did not get much traction, no alternative is being developed.
- Smart phone apps can use data plan to send SMS (not over SMPP) and bypass carriers' SMS communication channel. iPhone's iMessage is the biggest trend changer here.
Despite the declining growth trend, SMS over SMPP, being a core communication protocol, will probably continue live in the carrier space for few more decade. That's strictly my personal observation.
Comment on usages of SMPP
SMPP requires specific knowledge about the protocol, and it takes time and patience to acquire that knowledge. It probably influenced the rise of other alternatives.
I have seen that developers are leaning more and more towards HTTP based communication. The implementation is custom. I have seen:
- HTTP communication using GET parameters. If synchronous acknowledgement is required, the call becomes a blocking, else a callback is used to report acknowledgement.
- HTTP with using POST parameters. XML is being used to describe the SMS.
- Web service
Some rarely used alternatives are:
- SMTP. For sending from an entity.
- IMAP. For receiving.