What's more, RFID raises privacy concerns that ShoppingTrip 360 might not. Infosys says that its system is completely anonymous, unless the consumer agrees via cell phone to tell the system who he or she is (and consumers can opt to identify themselves based on just their shopping-cart number). Infosys says that it will pay to install the sensors in stores, charging retailers only for the data that they want to use.

"I'm charging to tell them when stocks are reduced by a certain percentage, or when a consumer redeems a coupon through their mobile phone," says Sandeep Dadlani, global head of sales for Infosys's retail unit.

Exactly what the data will cost is not yet determined, says Gopalakrishnan. He says that Infosys is piloting the system at a number of large retailers in the United States, Europe, and Asia. Girish Ramachandra, head of the innovations practice for the Infosys retail unit, says that it is no harder to install its wireless sensors than to set up a wireless router in a home. Initially, it will take a week per store to deploy and test the system.

Infosys says that it is ready to offer three things: "heat maps" of stores that show levels of inventory, levels of inventory at the fronts of shelves, and concentrations of shoppers in the store; a smart shelf pad with a built-in wireless sensor that is powered by the store's lights; and a shop-by-cell phone option, which lets consumers get recommendations or coupons on their phones.

Infosys thinks that there will be many other applications it can develop for the system, such as a "perpetual checkout" service that would let shoppers ring up their goods as they put them in their carts, allowing them to walk out of the store when they are finished shopping. For apparel retailers, the company is developing smart mirrors that will recommend combinations of clothing and automatically notify salespeople to bring things for shoppers to try on. Infosys could develop an application to let stores employ the sensor networks to manage energy usage. And it intends to open its development platform so that other companies can create applications for the service as well.

Forrester's Lawrie says that without seeing the system in action in a store, it's too early to say how well it will work. But if the system works as promised, he says, "this would be a huge breakthrough."