Los Angeles-based mobile Wi-Fi network operator Boingo Wireless has made a major expansion of its network of Wi-Fi access points in South Korea, after signing a network access agreement with SK Telecom. Boingo said this morning that a deal will add 75,000 hotspots in South Korea, located in airports, hotels, convention centers, restaurants and office locations. Financial details of the agreement were not announced. Boingo said the new deal also provides its various roaming partners with access to the additional locations.