As Comcast prepares to activate its MVNO agreement with Verizon in the US – and possibly acquire its own spectrum again – the prospects for wireline-only, or mobile-only, operators look bleak in mature markets. According to new research by Ovum, the race towards quad play models is putting a tight squeeze on pure-play mobile operators in Europe, and the research firm calculates that, in the 10 markets it analyzed, smaller cellular-only players have only betweem 5% and 7% of the market (by subscribers), when mobile and broadband are considered together. Chief research analyst Mark Newman commented: “Even though most are still growing their share of the mobile market, they are excluded from the big-ticket bundled services and experience higher rates…