Korean LMS : similar to concatenated SMS?

What happens when I send a really long message through A2P line? Is it delivered in one piece to cell phone? Or is it cut into parts and delivered as multiple SMS? If so is the order correct?

Every company that needs to send long messages for whichever purpose faces these questions. And truth is – depending on a lot of factors the answer will be different.

Not all countries and networks support the so-called Concatenated SMS (C-SMS, Concats).

Concatenated SMS – a service, allowing delivery of SMS longer than the standard 160 GSM characters in one piece to the handset.

Number of SMS

GSM characters

Unicode characters

1 standard SMS

160

70

2 concatenated SMS

306

134

3 concatenated SMS

459

201

4 concatenated SMS

612

268

Basically, the process involves breaking the message first into multiple parts and then reattached together in the correct order into one message when delivered to the handset.

There is no fixed limit for concatenated SMS, depending on the device capacity it may vary. As for the destination and network – here’s the catch. CDMA networks do not support concatenation. So the messages will be delivered in parts to the handset, which is why for some countries SMS Hub providers always mention that they can not guarantee 100% delivery of the messages over 160 bytes (e.g. USA).

Another case where concatenation is not supported – South Korea. South Korea has a unique service called LMS (Long Message Service). Unlike other countries, for A2P providers Korean message length limit is different :

Message type

GSM characters

Unicode characters

1 standard SMS

90

45

1 standard LMS

91~2000

46~1000

From technical side, the process does not involve concatenation, the message is delivered in one whole piece from the Sender all the way to the handset.

The biggest difference and the benefit of LMS over C-SMS is it’s price. While A2P SMS providers charge the total price as SMS price x (Num. of parts in C-SMS ), Korean providers offer single pricing for LMS. It means, that no matter how long the message you sent is, 200 or 2000 bytes – you still pay the same price, while with C-SMS for really long promotional text you might have to pay 10 x SMS price.

 

Sending SMS to Korea

There are three major Mobile Carriers in South Korea : Korea Telecom, SKT and LG U+. These days, following the progress in 4G/5G… development, more and more people rely on various messengers rather than SMS. That is for personal communication.

When it comes to corporate use, SMS is still a very important tool in reaching out to the customers, be it advertisement messages or registration codes for some app or service.

When sending SMS to South Korea, there are certain specifics you should be aware of :

  1.  When sending SMS from abroad, the message length is limited to 90 bytes.그림1
  2. Messages beyond 90 bytes will be delivered in one piece, but not as commonly known concatenated SMS (concat, C-SMS). In Korea, there is a term of LMS (Long Message Service) for messages of 91~2000 bytes.
  3. One of the special headers might be added :
  • [Web발신] (“Sent from Web”), indicating that the message was sent via A2P route.
  • [국외발신] (“Sent from abroad”), indicating that the route used does not belong to a local provider
  • (광고) (“Advertisement”), indicating that message contains promotional information.

IMPORTANT! The first 2 headers are automatically added by the Mobile Carriers and are not counted in the overall byte count. Thus, if you are charged by your provider for adding these extra bytes… Well, let’s say you have a good reason to find a new one!

E-mail : sureminternational@gmail.com

SureM FAQ : What is OPT-OUT? What does [Web발신] mean?

Be it something basic like SMS length or definition of the “OPT-OUT” – in messaging business there are always questions to ask. At SureM, we are constantly working on collecting and updating the data on everything, from technical terms and definitions to latest SMS regulations updates.

SureM FAQ

2017-04-07 10;58;52

 

Feel free to pop in to check our some of the questions you might be interested in and email us at sureminternational@gmail.com to ask any that are not on FAQ.