Cox writes the obit on its mobile service

Cox Communications is ending its not-so-grand experiment with mobile on March 30. The cable provider said in a statement it would discontinue its wireless service on March 30, appeasing its mobile subscribers with a $150 service credit for every line deactivated. No matter how good ‘quadruple play’ bundles look on paper, cable providers can’t seem to get the wireless component right.

“Cox is working to make this transition as seamless and easy as possible for our customers,” EVP of Product Development Len Barlik said in the statement. “We are proud of our employees’ dedication to delivering the excellent customer service that Cox is known for, and we will continue to keep our wireless customers’ satisfaction a top priority during this transition period.”

Cox originally planned to become a full-fledged wireless operator, buying advanced wireless service (AWS) and 700 MHz at auction in the cities where it offers cable service. It tapped Chinese vendor Huawei to build a CDMA network, partnered with Sprint (s S) to provide roaming access outside of its territory and even hinted at a future LTE build to add mobile broadband to its already extensive home and business broadband service portfolio.

However, Cox got off to slow start, launching it’s “Unbelievably Fair” service in just a handful of markets in late 2010: a year behind schedule. Cox added more markets in 2011, but it showed signs it was having second thoughts about its mobile strategy. Rather than use Huawei network gear, Cox turned to its roaming partner Sprint to power its service while it expanded into new cities, until May when it revealed that it planned to junk its networks entirely but continue to provide service as a Sprint mobile virtual network operator (MVNO).

Now, with wireless available in roughly half of its cable territory, Cox is abandoning mobile entirely. Why did it fail? With the waves of consolidation in the wireless market, it’s becoming increasingly more difficult for a small wireless operator to make it on its own. The money Cox would sink into its own infrastructure wouldn’t produce much in the way of returns. While remaining an MVNO would allow it to maintain its quad-play bundles, the math probably stopped making sense as demand for home phones wanes. Cox was probably merely replacing its customers’ cable telephony service with a far less profitable mobile phone.

The big question is what Cox will do with its spectrum. Cox has already said it plans to sell off whatever networks it has built, but it will find few buyers. A CDMA network using Huawei gear at AWS would be incompatible with all of the major operators networks. The spectrum licenses, however, would be valuable to almost every operator. Leap Wireless (s LEAP) and MetroPCS (s PCS) could use the spectrum to grow their regional CDMA and LTE footprints. Verizon Wireless (s VZ) and AT&T (s T) both are using 700 MHz for LTE and plan to expand into the AWS bands. T-Mobile’s high-speed packet access plus (HSPA+) network is built at AWS. Sprint is probably the only operator with no conceivable interest in the spectrum. If a bidding war hasn’t started already, Cox is definitely going to see a lot of suitors.