One of the biggest challenges for densification is the red tape that many cities wrap around site approvals for small cells. In markets where local or national governments have relaxed their regulations, such as Japan, there is a direct correlation to the progress of small cell roll-out – but these countries are few and far between still. Elsewhere, the USA has driven many of the most progressive ideas about standardized rules and blueprints for small cell sites, but these have foundered on the battle for control between the FCC and the municipal or state governments. Now London is trying to do its bit to push the cause of dense urban 4G and 5G. The UK capital’s mayor, Sadiq Khan, has…