Friend and I are both on spark here in Chch on a corporate plan. We both have Samsung s5 mobiles. 

 

Our office gets awful lte reception, so I disabled it by selecting WCDMA/GSM rather than WCDMA/GSM/LTE however frequently it drops off and I lose signal. Now this happens to both of our devices, no correlation between locations etc. 

 

Any idea why? I get awful battery drain with LTE enabled, but can't risk missing important phone calls! 

 

This never happened on Vodafone, so struggling to explain how spark is dropping my connection for around 30 seconds or so randomly on Samsung s5 devices.