Calder On Technique Based Integral Equation Methods In Computational Electromagnetics

The walkie-talkie technology is in the process of "analog to digital", DMR is oneof the important standard. The DMR standard for digital walkie-talkie has unveiled inthe market, it has the following advantages: twice the capacity of analog technology,integrated data applications and superior voice quality.Howerver, currently, DMR digital radio has the following deficiencies:(1) Its operating system which is not the smart operating system does not supportMulti-tasking.(2) Its simple structure and single function makes it be hard to integrate otherapplications, this weaken its market competitiveness(3) Its primitive graphical interface affects the user experience.Based on the open source Android operating system which has the followingfeatures: support multi-tasking, integrated rich application functionality and excellentinterface effects. We designed the DMR upper layer protocol software on the softwareradio platform. Software meets the DMR protocol specifications and is easily ported toother systemsFirst, we designed the overall function of the DMR upper layer protocolsoftware.With the effect of Android’s excellent graphical interface we provide userswith beautiful, simple graphical interface and good operability, to provide users with abasic voice calls, SMS services and database management functions.Second, we designed the DMR the upper protocol software services managementframework. Detailed definition of the signaling in line with the DMR the call controllayer protocol specification as well as a variety of business applications complete fromtop to bottom in the software process, software detailed design of the module, themodule and its implementation of the interface method, effectively support theoperation and management of the communications business.Third, we designed the transmission scheme of the speech data in the underlyingphysical device.Through Linux device driver we control the audio codec, voicecompression as well as on the main chip data transmission path, so that the threecoordinating work together to complete the capture and playback of voice data.Finally, we test the service processing capability of the software. Set up a testenvironment, design test cases to verify the validity of the data processing softwarerunning on the Android system robustness and reliability as well as the underlyinghardware voice module.Android provides DMR excellent graphical interface, intercom application makesthe user experience more fluid, at the same time, build on the Android platform WIFI,GSM and multimedia features make the device more competitive. The development of DMR communications expanded the Android wireless capabilities, to completeemergency communications in the case of other network is not available or is notsmooth, and has some practical value.