In this paper, we have shown a major element occupying the large portion of software communications architecture (SCA)-based software defined radio (SDR) handheld embedded system and an important feature for implementing a high speed broadband radio to an SCA waveform through a couple of experiments. First, this paper identifies the main items possessing the large portion of SCA-based SDR handheld embedded system by the experiment on the target platform which is similar to a commercial mobile handheld system. Both the world interoperabillity for microwave access (WiMAX) and high speed downlink packet access (HSDPA) waveform software packages are used as an SCA waveform application. This paper also presents the results of the relative binary size distribution of SCA software resources for looking for the major elements making an SCA-based SDR handheld embedded system heavier. As a result, when focusing on the relative weight portion of SCA core framework (CF), the SCA CF takes 16% up and others have 84% out of the whole binary size distribution of SCA software resources. The results of the experiment give us notice that the weight portion of SCA CF is minor and compatible with the overall software binary size needs of an SCA-based SDR handheld embedded system, on the other hand, the practical problem on the lightweight is in a common object request broker architecture (CORBA) and extensible markup language (XML) parser resources. Second, this paper describes an important feature for implementing a high speed broadband radio to an SCA waveform and presents the performance evaluation results of the SCA port communication on both power PC (PPC) 405 and x86 processor platforms. The PPC 405 platform, which is similar to a commercial mobile handset, takes the value of average round trip time (RTT) with a maximum of thirty six millisecond. The x86 platform, however, which is analogous to a server platform, maintains stable micro-second resolution. From our experiments, we observe that rapid SCA port communication, sufficiently less than the frame length of high-speed broadband radios, should be provided for serving those radio services in a commercial handheld system based on the SCA.