Middleware transports in a real-time embedded environment

Embedded systems are undeniably migrating from hardware to software, and software systems are undeniably using more standard software components. Examples include the use of commercial operating systems and middleware products such as web services and CORBA. Some software developers buck the trend with custom software components in an attempt to gain a short term size or performance advantage, but with the increasing speed of processors, increasing size of memory and increasing demand for more functionality; the long-term trend is to avoid custom components when standardized components meet the need. Using standard components allows developers to reduce time to market or spend their time increasing the functionality and sophistication of their applications. The JTRS standard supports plug-n-play systems by standardizing the APIs that access and control radio applications and components. These APIs are expressed in both C language and CORBA IDL. Proponents of the CORBA APIs perceive advantages in modularity, reliability, and increased functionality. Proponents of the C language APIs do not extol its virtues, but instead point to CORBA tendencies toward bloated size and performance. These perceived disadvantages are being overcome. As systems grow larger they become more brittle, take longer to develop, and reduce programmer productivity. Programming teams can regain the advantages of small system development by partitioning systems into independent parts. These parts collaborate to form the complete solution. A partitioning strategy will only be effective if the partitions are highly cohesive, and the inter-communication mechanisms work well. This paper compares communication mechanisms for embedded systems development. Unlike middleware alternatives such as web services; CORBA is becoming increasingly available on DSPs and FPGAs. CORBA is a candidate for many radio applications. CORBA is often a superior strategy. Its advantages are compelling and its potential disadvantages can be mitigated with customized transports. This document does not contain technical data as defined by the International Traffic in Arms Regulations, 22 CFR 120.10(a), and is therefore authorized for publication.