Default losing connection to google servers

my nexus 5 is stock , the signal is fine i dont connect using wifi as i have un limited data. However I notice that a lot of the time if i leave my phone idle , i lose connection to google servers. ie my signal bar changes from white to red. Any ideas how to solve this if i two finger pull down i can see the red signal then see it change white.
if i leave the phone for an hour or so will do the same , so i keep missing out on emails. If i put the phone in airplane mode it sometimes solves the issue for a day or two but always comes back