Design and application of data collection for bus fare collection system based on Wi-Fi technology

With the application of contactless IC card technology in the automatic fare collection system of urban public transportation, on-board POS machines are widely used in the public transportation fare collection system. In recent years, the proportion of customers using cards for consumption has been increasing, and the number of on-board POS machines in public transportation has also continued to grow. At the same time, higher requirements have been put forward for the public transportation fare collection system. At present, public transportation companies in various parts of my country have basically established traditional POS systems with wired access, as well as some GPRS/Zigbee wireless solution pilots. However, with the development of technology, the shortcomings of data collection in the existing public transportation POS system have further emerged.

Wired access to bus POS machines requires staff to read the data from the onboard POS machine through a data collector and transfer it to the data collection center after the bus returns to the terminal. The involvement of personnel makes the collection process inefficient and error-prone, and maintenance is also more complicated (see Figure 1).

On the other hand, due to the large number of buses and frequent network interactions, it is impossible to bear high operating costs. For example, paid communication services such as GPRS and CDMA can only be used as long-distance backbone network connection services, and cannot be used as a comprehensive bus charging network. We compare several wireless data transmission methods as follows (see Table 1).

The wireless communication and network technology carried by WI-FI just fills this gap perfectly. The rising trend of Wi-Fi network construction has made Wi-Fi the mainstream direction of wireless networks. From security, technical maturity, connection with existing networks, node management, QoS characteristics, and device interoperability, Wi-Fi has unparalleled advantages in short-range wireless technologies and can meet the needs of data collection in bus fare collection systems to the greatest extent.

Beijing CEC HuaDa Electronic Design Co., Ltd. (hereinafter referred to as HuaDa Electronics) has proposed a bus wireless POS access solution based on Wi-Fi technology based on the rapid development of wireless network data services. The POS wireless access method based on Wi-Fi technology can perfectly solve the shortcomings of traditional bus wired POS and existing wireless data transmission.

Using Wi-Fi wireless access technology, when the bus enters the terminal, the on-board POS machine automatically associates with the wireless AP/Router installed at the terminal. The AP can be connected to the data collection center via Ethernet. After the association is completed, the on-board POS machine automatically uploads the data stored on the POS machine to the data collection center, and downloads the blacklist and other content to be downloaded to the on-board POS machine wirelessly. This process does not require the data collector to transfer data, and does not require personnel to participate. Multiple Wi-Fi on-board or handheld POS can access the bus fare collection system in a shared manner through AP and communicate with the data collection center. Customers can flexibly choose the location and number of AP installations and adjust the coverage range according to the actual situation of the terminal. The use of Wi-Fi wireless access technology makes the data collection of the bus fare collection system more intelligent and easier to maintain (see Figure 2).

Wi-Fi wireless data transmission has the characteristics of low equipment cost, highly secure and reliable data transmission, flexible and convenient use, etc., which is very suitable for application on POS machines. The Wi-Fi operating system can be upgraded remotely through the network, which is very flexible and convenient. It can provide wide-area wireless IP connection, suitable for industry and enterprise users to carry out wireless data applications, and provide high-performance wireless access for scattered remote access points.

Wi-Fi main features:

1. Long transmission distance and wide coverage. A single AP can cover up to 10,000 square meters

2. High transmission rate. The rate can reach 11Mbps.

3. The system transmission capacity meets the requirements. Wi-Fi technology is particularly suitable for POS systems, which need to transmit large amounts of bursty data.

4. High security. It provides "security multi-mode" capability and supports WAPI/WEP/WPA/WPA2 security standards. The security standards can be configured through software.

5. Good scalability. Considering the growth and changes of future services, it should have sufficient scalability, including the provision of multiple access methods and access scalability, bandwidth expansion and smooth rate upgrade, and processing capacity scalability. Relying on the mature technology brought by the large-scale deployment of Wi-Fi networks, various emerging Wi-Fi devices, existing network facilities, architecture support, and rich network knowledge, the use of Wi-Fi can minimize the adjustment of network architecture and existing equipment.

The wireless module customized by HuaDa Electronics for the bus fare collection system has a simple interface and is easy to use. Customers no longer need to pay attention to the details of wireless technology, but can directly and quickly enter the practice of wireless product development. This greatly speeds up the progress of product development and achieves an easy transition from wired to wireless technology and products. Currently, the wireless bus system based on HuaDa Electronics' WLAN technology has been deployed in several large and medium-sized cities in China and has achieved good operating results and has been unanimously recognized.