Mobile Lowdown 5-25-11: 4G; Cox; Nokia / ZTE; Sony; Instagram; AdSense

A look at some of the big stories in mobile today: Cox drops 3G; UK gears up for first LTE trial; Nokia (NYSE: NOK) and ZTE scramble to put out the first Mango handsets; more security breach woes for Sony (NYSE: SNE) — this time around Sony Ericsson; (NSDQ: ERIC) Instagram’s four-million milestone; Google (NSDQ: GOOG) expands AdSense for mobile.
Cox: Cable operator Cox Communications is abandoning its plan to build out a 3G network, and will instead continue to use an existing MVNO agreement with Sprint (NYSE: S) to provide mobile services to its customers, according to a report in FierceWireless. No word yet on what will happen with the infrastructure already built out, or with the spectrum owned by Cox.
4G UK: Everything Everywhere (the JV between T-Mobile UK and Orange UK) has announced a joint, live trial for LTE services — the first for the country. Read more on this here.
Nokia and ZTE: Here’s one consequence of Microsoft getting more OEMs to sign up for Windows Phone 7: it might kick Nokia into a higher competitive gear. Read more here.
Sony: So many security breaches are getting piled on the company that it’s almost hard to track them all, although one blogger has counted up to 10 as of yesterday. One of the more recent attacks: the Canadian eShop for Sony Ericsson mobile phones and accessories, where some 2,000 names and email addresses were stolen, and 1,000 of them posted online by the hacker who put a claim on the attack.
Instagram: The photo-snapping, filtering, and sharing app is ramping up users fast, even though it still has only four employees: in its first seven months of existence, it’s clocked up more than four million users, and with an average upload rate of 10 photos per second (via TechCrunch). Sounds like an acquisition target to me.
Google AdSense: The company has extended its mobile AdSense service — which delivers text-based ads alongside mobile web pages — to 15 more countries: Argentina, Brazil, Chile, Colombia, Czech Republic, Hong Kong, Indonesia, Malaysia, Mexico, New Zealand, Nigeria, Philippines, Slovenia, Thailand, and Turkey.