InHand Networks

National Earthquake Administration Wireless Communication Solution for Detecting Station Network

一、 Solution

1.1   Requirement Analysis
      The solution of National Earthquake Administration’s detecting stations network aims to build up a digital wireless network. The network, using wireless network as its communication framework and containing two hundred floating seismographs which are configured with wireless communication system, can realize the real-time communication between the control center and floating devices together with a control center built up in Earthquake Administration monitoring center. The wireless communication system adopts CDMA routers of mobile operators’ CDMA 1x network and employs VPN based on L2tp or IPSec as its network method.
    ★ Special requirement for wild end(CDMA ROUTER)：
         Strong adaptability to circumstance, low power dissipation and failure rate,  qualified with certain defense grade and remote control function.
    ★ Special requirement for devices in monitoring center
        Fast-speed construction of VPN tunnels and the small data transmission delay
1.2    Design
      This project utilizes operators’ CDMA network to build up the whole system, CDMA employs wireless routers as floating and wild floating monitoring devices to access Internet, and uses the private line method to access Internet in the control center. Thus the data transmission is realized between floating device and the control center, while VPN connection method helps save the private line cost and ensures the security and reliability of data transmission. The control center, which is able to monitor more than six hundred floating seismic devices at one time and store certain amount of data, can implement device monitoring with the present real-time control and the remote control software of seismic devices. At the same time, it realizes real-time data transmission of some or all remote observation points according to practical work. The whole network topology map shows as below:
     Large-screen display system in the control center provides the real-time display on work state and waveform of wild stations.
     Meanwhile our solution offers an extended application: engineer mode.
     After VPN connection between remote earthquake observation devices and VPN devices in the control center succeeds, engineers out on business can connect to the control center in VPN method (PPTP or SSL) to realize real-time monitoring on seismic devices.

二 Explanation on Wireless Device
　　InRouter 319CI of Beijing Inhand networking CO., LTD is used as CDMA wireless transmission device in this solution. This product shows good quakeproof, waterproof, dustproof, and pressure-resistant performance, which especially suitable to field prospecting, environmental protection, weather, earthquake and other special industries.
2.1   Summary of InRouter319CI
　According to requirements of industrial Ethernet development, InRouter series utilizes operators’ (China Unicom) network as its bearing network to realize remote wireless transmission. As the CDMA gateway and router between remote control center and center control system, it has realized remote inter-access of industrial Ethernet network devices.
　　InRouter adopts standard Ethernet protocols for the network routing. Aiming at the access restriction of operators (China Unicom) to external network IP data, it utilizes VPN technology based on IPSec to realize safe interconnection of remote networks and the machine-to-machine data communication based on standard TCP/IP protocols. VPN technology based on IPSec can build up encrypted tunnels of remote networks through Internet to realize safe interconnection, construct VPN for industry field, support protocols and applications based on TCP/IP in industry field.
　　This product has 10/100M adaptive Ethernet and serial interfaces. It will be widely used in many fields such as remote/field data collection, remote monitoring and control, family gateway, video transmission, digital signal processing, network storage, VPN, etc, and specially adapted for remote data transmission of distributed geographical positions, short construction period, small and medium data flow, complicated network construction and multi-layer protocols support need.
　　In this solution, we have selected InRouter 319CI, which is uesd in many special fields, to satisfy customer requirements. In the hardware configuration, this product adopts chips of industrial grade as its core chips to meet the temperature and other environmental requirements. The engineering plastic shell design with good quakeproof, waterproof, dustproof, and pressure resistant performance, is epically adapted for field prospecting, flied floating operation, environmental protection, weather, earthquake and other special industries.
2.2    Technological Parameters
1、InRourter 319CI
physical property
External
feature Dimension 276.5*337.5*98.5mm
Weight 1465g(no antenna )
Environment Temp -25 ~ 65℃
Keeping Temp -40 ~ 85℃
Comparative Temp 95%( no coagulation)
Interface UIM/SIM card 2.8~3V
Serial Interface 9-needle aerial waterproof joint
Ethernet Interface
Power 3-needle aerial waterproof joint
Antenna 50Ω/SMA
Operating Display Panel LED Output
Power Supply Broad Voltage 9～24 VDC
Operating Current Standby 120mA@+12VDC
Communication 2800mA@+12VDC

2.3 Advantage and Feature
    Perfect Reliability
1、 Adaptive capacity to Adverse Environment
       ★ Industrial Temp range: -25℃-65℃ ;
       ★ Cold Starting: -25℃, 10 hour;
       ★ Waterproof and Dustproof: IP54
       (5: Anti-dust: Thorough dustproof protection is impossible, however, we can ensure the dust amount not do harm to devices, 4:Anti-water spraying:

Resistance against water sprayed form every direction to the cabinet)
       ★ EMC Index: Surge: Power Supply circuit 2.0kV (Common-mode), 1.0 kV(Differential-           mode)
        ★Voltage Sag: Stable operating voltage with little fluctuation, Max measured value is
          192mv
        ★Power Dissipation: Standby 120mA@+12VDC Communication 280mA@+12VDC
Factors Supporting Indexes Above:
a. Chips with industry-grade temperature range (-40℃-85℃) are adopted：
     Full-speed work and wide-range temperature variation will reduce product lives or  cause them to work out of order. Therefore elements with industrial temperature range is required in adverse circumstance, which can work normally and realize all functions in a range from -40ºC to 85ºC. These elements with good quality and reliability ensure normal performance as the limiting temperature varies.Products with commercial-temperature elements usually work inefficiently in adverse  circumstance and run high risk for projects.While the construction cost of seismic stations is high, products used in remote areas especially ask for high reliability and low risk products.
b.   waterproof ,quakeproof sealed cabinet and aerial waterproof joint:
    The sealed cabinet utilizes engineering plastics, to be light and solid, and to meet the requirements of professional devices in earthquake field. This design also meets the needs of field floating exploration.
c. Hardware design aims at EMC index optimization Optimal deigns on anti-surge, anti-static and EMI.
d. Mode optimization solution aims at solar battery power supply
2. System redundancy backup mechanism:
    The system upgrade utilizes our patent technology, which executing the redundancy backup of firmware programs inside the router with two FLASH, to ensure the system reliability.
3. Legal MAC address:
      InRouter series applies to IEEE for unified MAC address distribution to ensure that the network card address of every hardware device is the only one in the world. This avoids address conflict for costumer use and promotes network security. Customers can visit http://standards.ieee.org/cgi-bin/ouisearch to check

whether the MAC address is legal.
      Good Stability of InRouter Series
   Long-time and massive stable work without manual intervention
      Large Scale: Practical case: GEHC device network for 400 VPN, Liaoning Sports Lottery network for 500 VPN
    All-time operation: Projects above are 7*24 hour operatin
     Complicated operation circumstance with good performance
    Good compatibility with operators’ network: Recently our products have been in field operation in thirty-three countrywide areas (including Hongkong, Macao and Taiwan) showing the compatibility with every network and good performance.Excellent interoperability with mainstream VPN devices: Interconnection with products of  many mainstream VPN manufacturers has been realized without failures, such as :Cisco, Netscreen, Huawei, OLYM-TECH, Capitel, Huatang Network, Beyonder, QNO, linksys、NESCO ,etc. It fully ensures investment benefits of customers and the future network rebuilding and upgrading.With frequent power-off and power-on, the reentry of testing system succeeds with 100% rate.
Factors Supporting Indexes Above:
   a、Hardware Watchdog
   b、Software self-checking and self-recovery mechanisms
       The software design involves multi-level system detection function, which help monitor system’s operation state and implement self-recovery function when the system is out of order, and then recover them. For example, it can detect exception occurs in the mode, signal, SIM card, VPN tunnel, program fleet etc,.
c、：Multi-link detection and self-reconnection functions
        Short reconnection time and success connection ratio 100% connecting
d、Abundant project practice, gelling and adjustment to improve products
        Good security of InRouter series products
In this project InRoute series employs CDMA network for communication, which is described before, to process higher security compared with other communication methods.
      InRouter series has MAC address binding function, which effectively protecting from the detection and attract of remote data and promote the network security.
      InRouter series uses VPN line in data transmission. All data are encrypted in VPN tunnels so that they can’t be acknowledged by other people and data transmission security is ensured.
      Accessibility and Easy-maintenance
Export and import configuration function helps with batch configuration of devices, which adapted for large-scale application and guarantees the consistency.The “Quickset” page for customers can accomplish all settings through “One-page-setting” to reduce the complexity and of multi-page setting.
         Manageability
a、：Local and remote upgrade
      With local or remote upgrading firmware programs, customers can conveniently maintain their nationwide devices and decrease the maintenance cost.
b、：Remote wakening function
     When remote devices are off-line, customers can activate devices with telephone dialing-in, automatically build up connection and VPN tunnels, to realize remote management, save the flow cost and reduce system load.
c、：Customer data triggering up-down line
      Connection and VPN tunnels are automatically built up when local data flow occurs.This accords with the working mechanism of seismic devices, save the flow cost and cut down the power supply dissipation.

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