What you are seeing is the mobile network sending data then going back to sleep. It is similar on your mobile phone when you see 3G and then 3G+ or H then H+ when you use data. This is used by carriers to save bandwidth when you are not transmitting data so they put you on a low bandwidth service WCDMA and then when they detect you start transmitting it will switch up to HSDPA/HSUPA. When it sees no more traffic it will drop you back.
Things you can do directly to "fix" this is:
a) constantly send traffic. Stream a radio channel and it will probably stop but cost you a lot of data.
Alternatively to ignore these entries:
b) Go to Configuration - Alarms > Event Settings and tick "Include event number in the event log and Email, SNMP traps, SMS or Syslog messages"
Go to your event log and find the "code:" number for these two entries.
Go back to Configuration - Alarms > Event Settings
Under "Do not log the following events:" type the two numbers such as "57,70"
untick "Include event number in the event log and Email, SNMP traps, SMS or Syslog messages"
Clear your log and it should be gone.