BARCELONA -- Mobile payments made in different parts of the globe were an important theme at Mobile World Congress this week, with leaders Visa and Mastercard announcing new services.Visa on Monday announced one of the most unusual approaches, one that relies primarily on older QR code technology through its mVisa payment service. It went live Monday for merchants and customers in India, Kenya and Rwanda and will soon be available in Egypt, Pakistan and a few other developing countries.The service allows merchants and consumers to make payments via a mobile phone and a QR code kept at each merchant's store location. Visa said the flexible nature of QR codes means that merchants do not need to invest in costly point-of-sale infrastructure.In the U.S., the implementation of more secure chip cards in late 2015 has been dragged down for months by backlogged certifications for new point-of-sale machines that could read the new chip cards. Merchants have also complained that chip card readers were also costly to install, given the need to change back-office connections.The mVisa service works this way: A customer scans the merchant's unique QR code posted or kept on counter inside a store. Then, the customer inputs a payment amount on his or her phone for an item purchased. The store clerk then also receives a verification of payment, usually through a text on a mobile device.Visa said the service will also work with in-home purchases from Tata Sky, a wireless service provider, by scanning a QR code from a mobile phone directly from a TV screen or online site. Also, consumers in Mumbai can pay home-heating gas bills from Mahanager Gas with the mVisa QR code printed on a bill.Avin Arumugam, senior vice president of Visa's internet of things division, said the service supports card accounts issued by Visa and Mastercard and will soon support American Express. It also supports RuPay Credit Card in India, he said.While the service has only just started, it is destined to grow, especially in India, Arumugam said. That's partly because the government of India discontinued its two largest rupee notes worth 500 and 1,000 rupees in a sudden move in early November."The move from cash to electronic payments is growing," Arumugam said in an interview on Tuesday. Electronic payments of all kinds, including mobile, were larger than cash payments globally for the first time in 2016, he noted.Visa and Mastercard have shown a willingness to adopt various old and new technologies to expand the use of their credit card networks. In addition to user older QR card technology, Visa relied on NFC for payments at the Rio 2016 Olympic Games last summer.Separately at MWC on Monday, Mastercard announced a partnership with Oracle to help streamline digital payments for stores and restaurants.The companies will further expand the use of a mobile app called Qkr! with Masterpass, which lets consumers order and pay in advance for goods and services via smartphone.The service is described as a quick way for customers to order drinks or food at a restaurant without waiting for a server. But it will be expanded to other services as well. Oracle's technology will be helpful, for instance, to allow retailers to provide a smooth checkout experience to customers across different payment channels, Mastercard said.Other details on Oracle's involvement and technology used for this announcement were not available.Mastercard named several pub chains using the service already in England, but plans to expand it to the U.S. and five other countries in 2017 to let users pay in advance via smartphone for gasoline, sporting events, parking and more.While some waiters have complained about mobile payment services that reduce their interactions with restaurant customers and the reduced possibility of tips, Mastercard said the expansion of Qkr! Is all about improving customer service."I don't necessarily know if this service replaces a waiter, but it can mean a customer doesn't have to wait for a waiter to come back to hand them a check," said Kiki Del Valle, senior vice president of Mastercard digital payments, in a telephone interview. "It's about delivering what the consumer wants and ...providing customers a choice."