It is an early summer day in an old neighborhood southwest of Shanghai, and shrubs are blossoming around benches on which people sit and chat.

As one of the world's busiest and most intensely managed public spaces, Shanghai now has a whole other whirl of activity and social interaction going on, one invisible to the eye.

For the first time in three years, Chen Guozhen can relax and let her husband, who has Alzheimer's disease, walk alone in the sunshine without worrying about losing him in the crowd.

"He is wearing this magic watch," Chen, 60, said, pointing to a black plastic watch with four giant buttons next to a square screen.

If her husband presses the red button, she said, "I get text messages on my cell phone that tell me where he is."

The watch, courtesy of China Mobile Group Shanghai Co Ltd (Shanghai Mobile), a subsidiary of the country's top telecom carrier, is just one demonstration of the country's bid to turn the city into a wireless hub.

With little fanfare, the city has become host to yet another layer of infrastructure, a random, interlinking constellation of what are called "wireless access points".

Walking the streets of Shanghai today means walking amid an unseen web of WiFi.

After building a 4G TD-LTE showcase network at the Shanghai World Expo in 2010, the company announced pilot plans to create a large municipal WiFi grid, stretching wireless access across the metropolis, with the goal of bringing free or low-cost service to all residents.

According to Xu Da, general manager of Shanghai Mobile, China Mobile expects to invest 13 billion yuan ($2.05 billion) over three years to deploy seamless mobile connections in the city, under a deal signed with the Shanghai municipal government last year.

Total investment will exceed 22 billion yuan during the 12th Five-Year Plan (2011-15).

According to Mao Weiliang, deputy general manager of the data service department of Shanghai Mobile, the framework of the Digital City Shanghai project has four pillars: network deployment, application development, cloud computing and information security.

Even though it boasts a world-class 2G network, China Mobile must still deal with the explosive data traffic led by smart devices, which might erode network resources for simple voice activities.

Its 3G network, the indigenous TD-SCDMA, has almost blanketed the city with some 6,000 base stations, but it needs diversified mobile terminal portfolios to enrich services for 3G users.

In terms of TD-LTE, it has deployed 200 base stations in the most densely populated urban districts, such as Lujiazui and People's Square.

All these factors drove the company to transmit its 2G, 3G and 4G signals - which are still in the test stage - to WiFi. That move was aided by the proliferation of more affordable wireless routers and networking devices.

It has so far set up more than 40,000 WLAN access points in the densely dotted city hubs, and the number is expected to triple in two years.

The company will also help establish 443 philanthropic hot spots around medical facilities, educational centers, transportation hubs and government agencies with 9,466 access points by next year, Mao said. "Each user can enjoy two hours' free access to the networks, before they are transferred to fee-based services."

In terms of applications, the framework of the Digital City project includes the development of application systems for telemedicine, e-commerce, e-government, distance learning, city management and much more.

Local residents can log onto the Wireless City website to enjoy nearly 50 types of urban information services covering government affairs, public utilities and personal life via mobile phones, personal computers and iPad-like Internet-enabled devices.

The project has become a platform for the government to release real-time information and extend assistance to the public.

For instance, the smart watch offered to Chen was part of a coordinated effort between the telecom operator and the office of the municipal Old-age Work Committee in Putuo district, where 150 similar watches were distributed free to poor households. The government will pay for the 29 yuan monthly fee over the two-year pilot program.

Another endeavor is offering health consultation and diagnosis services to users who live far from medical facilities.

In the Women and Children's Medical Center of Minhang district, a renovated "wired" medico-physical bus has carried out health checks for more than 20,000 retired women since a pilot program began in April last year.

According to Xiao Liping, head of the hospital, residents only need to swipe their tailor-made digital medical record cards and go through a series of gynecological examinations on the bus.

"The computer collects the information and transmits to the data center simultaneously."

Users can also buy movie tickets, order take-out meals and make restaurant reservations.

By linking its site to various merchants, China Mobile aims to address the great financial pressure that halted similar projects carried out abroad.

Tang Jiajie, a white-collar worker at a foreign company, used to order take-out meals based on leaflets handed out at the exits of subway stations. But now he logs on to the Wireless City webpage through an iPad to order fast food ranging from set lunch boxes to pizzas and noodles and pays online.

"You get different tastes, and don't bother to pay with cash," Tang said as he munched on a hamburger that had just arrived as he sat inside the downtown Huaihai Park.

In the small browser window of his Macbook Air, an antenna of sorts, he found himself at the nexus of any number of the wireless networks that have come to cover the city.

"I do not necessarily have to go back to the office at 1:30 pm to get on the Web. I get it right here," he said.

hewei@chinadaily.com.cn