Batch SMS
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      Batch SMS Best Practices

      The purpose of this article is to provide guidance on maximizing the effectiveness of Batch SMSs while minimizing costs per message and avoiding filtering by cellular carriers. Batch SMSs are highly efficient for reaching a large audience.

      Batch SMS Best Practices

       

      The purpose of this article is to help you maximize the effectiveness of your Batch SMSs by reducing the cost per message and preventing filtering by cellular carriers.

       

      Batch SMSs are a very effective way to reach a large number of clients, such as active members or prospects. However, best practices should be followed when sending Batch SMSs.

      •  Message Size
      •  Characters Used
      •  Per Carrier Limitations
      •  Recommendations

       

      Message Size

      Wireless carriers charge not by "SMS" but by segment. One large SMS may include multiple segments. Each segment is made of 70 or 160 characters depending on encoding - see below. MMS messages sent in Opus1.io equal 8 segments.

      Characters Used

      Opus1.io supports both GSM-7 and UCS-2 encoding.

       

      GSM-7 is a character encoding standard used for commonly used letters and symbols in many languages.

        • It uses 7 bits to send a single character/symbol on GSM networks. As SMS messages are transmitted as 140 8-bit octets at a time, GSM-7 encoded SMS messages can carry up to 160 characters (140X8/7=160)
        • You can view the basic character set for GSM here.

      UCS-2 is a character encoding standard used if a message cannot be encoded using GSM-7 or when a language requires more than 128 characters to be rendered.

        • It uses a fixed length of 16 bits (2 bytes) to send a single character. As SMS messages are transmitted as 140 8-bit octets at a time, UCS-2 encoded messages can carry up to 70 characters (140X8) / (2X8) = 70 
        • UCS-2 can encode anything in the Basic Multilingual Plane

      If the above doesn't make any sense to you, that's ok! 🙂 Just know that in order to limit the size of your Batch SMS (in number of segments), and therefore its overall cost against your monthly quota, it is preferable to use simple characters - if you use other characters like emojis (🚀, etc.) or international / accents (é, ü, etc.), Opus1.io will display a warning. This will result not only in higher overall monthly SMS costs but could potentially cause some messages to be filtered (not delivered) by cellular carriers.

      Per Carrier Limitations

      While Opus1.io strictly follows every best practice, such as registering your number with the campaign registry, which ensures your SMSs are not being filtered as spam, there are still limits that are out of our control. For example, T-Mobile has a limit of 2000 segments per day per registered phone number, those limits can change over time. 
      The MMS file size limits vary between the major carriers as well. Bandwidth, our texting service provider recommends sending attachments no larger than 500kb to ensure your messages are delivered. 

      Recommendations

      A large SMS sent to 800 students which includes special characters can account for a very large number of segments:

      8 segments ( ~500 character message with special characters) * 800 students = 6400 SMS counted against your SMS monthly quota.

       

      Therefore, opus1.io recommends adhering to the following guidelines when sending Batch SMSs:

        • Don't send batch SMSs to too many recipients at once - your SMS segment sent count can rise quickly, so try to avoid sending Batch SMSs to too many people at once.
        • Preferably, use simple characters (no emojis, etc.) - See GSM-7 above.
        • Keep the message short - don't send huge messages and if more details are needed, include a URL to your website where recipients can find more details.
        • Do not use public URL Shorteners: Shortened URLs (bitly.com etc.) are often a sign of spam for wireless carriers so using those may result in your SMS being filtered - use opus1io integrated URL Shortener!
        • Send Images With Caution: Since sending an MMS message equals 8 segments, your sent count will quickly rise. Be absolutely sure if you're batch sending an image, you're only messaging the clients you want. If wanting to send an image to several hundred clients, you might consider sending in an email instead.