Is it unreasonable to request that my husband switch off his mobile at night?

I think my husband is addicted to his mobile; he thinks I'm unreasonable. He frequently gets work related calls at night - which I figure can't be avoided, but he also gets texts and calls from work mates pretty much every night. He then might spend half an hour or more talking to these people, whom he presumably sees all day anyway. These guys (most of them don't have families of their own) also occasionally send drunken texts and pictures at any hour of the night and because the phone is never off, the glow from a silenced text (or the beep of an unsilenced one) wakes me up. My husband sometimes sleeps with his phone and has been known to respond to these texts throughout the night (occasionally sneaking out to the toilet or kitchen to avoid detection). He also checks his phone incessantly. It's a real source of friction between us because his mobile phone intrudes upon our family life and I just can't seem to convince him that it's getting out of hand. Am I being unreasonable?