An overview of the commericial RTOS market....
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Application-Specific RTOSes
The communication arena is a priority for RTOS vendors as they shape their products for the next century. These vendors are under intense pressure from Internet and wireless designers to have integrated, feature-rich products.
By Janine Sullivan
Internet connectivity is no longer reserved for the PC, and it will probably only take a few years before Internet-enabled smart devices are a part of everyday life for many consumers around the world. In order to create these smart devices, programmers and designers need to use a real-time operating system (RTOS) ¥ the embedded brains of the smart device, which is software that provides functionality including task control, memory management, communications, and access to other devices.
Selecting a commercially available RTOS for the latest communication devices requires careful consideration by programmers and designers. Recognizing that malfunctions and delays can cause significant problems for many communication systems, RTOS vendors are concentrating their product development efforts to support the latest telecommunication and data communication applications.
A global market
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The embedded systems marketplace is expanding to include high-volume, short-life-cycle Internet and wireless products. CMP Media's Electronic Market Forecasters estimates that the global RTOS market grew from $305.4 million in 1998 to $362 million in 1999. Software industry giant Microsoft has entered the RTOS market and, over the last few months, the major players have consolidated, as evidenced by first-ranked Wind River Systems' purchase of second-ranked Integrated Systems (see Figure 1). (For more on this acquisition, see "Software Showdown" Communication Systems Design)
Increased demand for embedded systems devices from the fast-paced communication industry, coupled with Microsoft's entrance into the RTOS market with its Windows CE product may have been a wake-up call to an industry known for its relatively relaxed product-development cycles. Now, like most other parts of the communication industry, RTOS vendors are finding themselves under pressure from Internet and wireless manufacturers to deliver products quickly and with low cost.
With the market changing and the major players constantly shifting, where does the communication device designer look for an RTOS core? Simply put, the choice is either to select a product from an established vendor, such as Wind River, Enea OSE, or QNX, or to use the relative newcomer to the market, Microsoft ( see RTOS Product Table and Vendor list.
Application-specific systems
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Designers can choose from a number of application-specific RTOS products for Internet-enabled devices that come equipped with real-time toolsets. Most vendors offer versatile licensing structures, and some, such as Wind River, provide full access to the source code for customization.
Wind River Systems' Tornado II is a software-development platform available for both UNIX- and Windows-based hosts. The package consists of three components: Tornado Tools, a set of cross-development tools and utilities; the VxWorks run-time system, a scaleable RTOS; and a range of communication options for the target to connect to the host. The company has also developed the Tornado for Embedded Internet product suite that is designed to simplify the addition of Internet connectivity to products that include printers, smart phones, and Web-enabled television sets.
In business since 1980, QNX offers communication systems designers its QNX Neutrino RTOS, a scaleable, MMU-protected, network-distributed OS. This POSIX-compliant OS supports threads and multiple platforms, and it offers full BSD4.4 and TCP/IP stacks. For the Internet device designer, this company supplies Internet and multimedia toolkits with prototyping tools, customizable Web browsers, and media players. The real-time libraries contain cross-development and self-hosted development environments, as well as real-time diagnostic utilities. All of the products work with numerous third-party modeling tools. Application source code and visual design tools are available in order to customize Internet and multimedia applications.
Current applications for the QNX RTOS range from wireless Web tablets to backbone routers. To simplify the design process, QNX device drivers and applications can be source-code identical across processors (MIPS, PowerPC, and x86, for example), so developers can write and test applications before a final processor is selected.
Counting Ericsson, Nokia, and Lucent Technologies among its customers, Enea OSE has been an RTOS supplier since 1984, first as a part of Enea Data AB and then as Enea OSE Systems AB since 1996. The company's products are designed to work with both single and multi-CPU systems, including those that have hundreds of processors from different vendors.
In addition to its OSE Kernel, OSE Soft Kernel, and OSE Soft Environment, the company offers a variety of kernel configurations and development tools, as well as a real-time toolset (which includes the OSE Illuminator, that performs debugging on the application level; the Program Handler; and the OSE Soft Environment). The OSE product also ports to numerous third-party toolsets.
Application-specific RTOS products such as those mentioned above can provide many benefits to communication systems designers. Lars ?sterberg, CEO of Enea, warns against an all-purpose OS: "A broad-based RTOS with enormous capabilities is virtually certain not to offer optimal performance for a specific application. Additional functionality is useful when tailored to a particular technology, but âfeature-creep' can also burden memory and increase the risk of failure." ?sterberg does not see the current marketplace as a space where an all-purpose RTOS can quickly become a dominant force.1 Focusing on a specific embedded market segment is definitely the trend for RTOS vendors.
Communication applications
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Currently holding the greatest market share (see Figure 1), Wind River attributes about 40% of the company's business to datacom/telecom applications. Ross L. Wheeler, director of engineering at Wind River's networking business unit, credits part of this success to his company's sensitivity to the needs of the communication market: "We offer a rich set of communication protocols and products that extend the core platform. And, as the largest RTOS supplier, we attract more independent providers of networking components."
The Bluetooth initiative (see Communication Systems Design's February 2000 Special Section on RF Design for a full Bluetooth technology article, pp. 66-64) is another consideration for many communication device designers. The RTOS vendors are addressing this specification as well. For example, in December 1999, Enea OSE Systems and Ericsson signed a cooperation and licensing agreement for an OSE RTOS tailored to Ericsson's Bluetooth core. Ericsson is also licensing its Bluetooth core with the Enea OSE Systems RTOS to the global market, with RTOS support available from Enea OSE.
Customers using QNX products to develop communication products include Cisco, GTE Mobilenet, Hughes Network Systems, IBM, Mitel, Motorola, Siemens AB, Telia, and Worldspace. According to Paul N. Leroux, Technology Analyst at QNX, one particular feature of the product that appeals to communication designers is that "new OS modules, drivers, and applications can be remotely updated on-the-fly, without removing the system from service." Additionally, the company supplies industry-specific toolkits with prebuilt, ready-to-customize applications. "So, rather than reinvent the wheel, designers can concentrate on differentiating their product," explains Leroux.
On the market for 3 years, the Microsoft CE product is being used by Honeywell, Inc. Radiant systems, Neoware Systems, and Siemens AG. According to Don Chouinard, marketing manager for Windows CE OS & Tools at Microsoft, the product is available with several modules for communication applications, and it includes options such as serial I/O support, TCP/IP, Network Directory Interface Specification (NDIS) for local area networks, and a telephony API (Microsoft did not respond to product inquiries, and is therefore not mentioned in the RTOS Product Table).
There are several other companies who sell RTOSes, and they can be found in the vendor table and vendor list immediately following this article. Many of the RTOS products have communication-specific applications and protocols.
Protocols and standards
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Some of the chief concerns in designing communication systems are the various standards, specifications, and protocols that must be satisfied. To be truly versatile for communication designs, an RTOS should not just support TCP/IP protocol stacks, but also some of the protocols slated for use in next-generation systems, such as XML, Universal Plug & Play, and Home Audio Video Interoperability (HAVI), a standard defined by consumer electronics companies such as Sony, Philips, Hitachi, and Sharp.
These protocol stacks are usually considered to be part of the system services, so they should be bundled into the OS. Unfortunately, different applications require different combinations of them. "This is bad for the RTOS vendors," explains Larry Mittag, chief science officer for Stellcom, "who would rather sell a small number of shrink-wrapped products. They are being forced into creating different packages to serve a large number of different vertical markets such as cellular phones and Internet appliances." For the system designer, the protocol support is imperative to enable quick time-to-market.
RTOS vendors seem to recognize that the communication industry is characterized by rapidly changing standards and short product life cycles. QNX has been offering Internet toolkits since early 1997 and, according to Leroux, "Internet and multimedia standards are changing so rapidly that you have to design flexibility into your system right from the start. An open software architecture with cleanly separated, dynamically upgradable modules is essential if you want to accommodate the latest technologies as they come down the pipe."
Toolsets
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Besides microprocessors and protocol stacks, communication systems designers also need to consider an RTOS' ability to interact with their existing toolset. For instance, does it work with the compilers, debuggers, and simulators that will be used to create the embedded system? Does the in-circuit emulator interface with the RTOS?
Wind River's Wheeler suggests that designers "look at the total project integration and development effort. Suppliers that can provide a higher percentage of your solution, particularly if it is already integrated, can dramatically improve time-to-market while reducing lifetime project costs. Until now, equipment vendors have faced significant challenges in pulling together solutions from disparate, often incompatible sources ¥ an RTOS from one supplier, management software from another, and protocol stacks and drivers from still other sources."
Reliability and time-to-market
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Besides the features and benefits of an RTOS package, designers for the communication market also need to consider time-to-market and reliability. Questions to ask include: How long will it take to develop the application? Does the RTOS truly support high availability? Is it proven, and will it help me retain my end-users? Does it offer a comprehensive, streamlined environment?
Eva Skoglund, a product director at Enea OSE recommends that designers "Look for RTOSes designed for high-availability and safety-critical applications, where the kernel, not just the tools, is optimized for such applications." Her point is that RTOSes designed to meet the most exacting requirements in performance and reliability will satisfy the demands of nearly all other applications.
Architecture and performance
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Perhaps the most obvious concern in selecting an RTOS is its performance, which is based on the quality of the core itself. Mittag suggests that designers fully explore the performance of the specific kernel they plan to purchase, including interrupt response time, speed, and memory requirements. He also notes that it is important to evaluate the quality of the available toolset, observing that "it is a major weakness if the vendor depends on third-party tools."
Skoglund suggests that when evaluating the performance of an RTOS for communication applications, designers should consider which RTOS will "enable you to give the most power, flexibility, and reliability to your customer, as well as enabling you to get to market quickly." She also points out that high reliability and flexibility are critical success factors, especially for mobile communication and Internet applications.
QNX's Leroux suggests that designers, "assume that the project will eventually become more complex than you anticipate. Then choose the RTOS whose architecture will help you best achieve, and manage, that complexity." For example, can your RTOS support a few dozen software processes ¥ or a few thousand? Also, does it provide extensive MMU support? Most RTOSes still use a flat architecture, without memory protection. As a result, adding a single line of code can force you to retest your entire system software stack. In comparison, an RTOS that provides memory protection for all processes, including drivers, makes it much easier to add sophisticated features and to reuse existing software in new configurations.
After settling on a product, it's a good idea to get and check as many references from your RTOS vendor as possible in your type of market to get a clear understanding of the RTOS vendor's service, support, and reliability.
Technology trends
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The technology trends shaping today's RTOS market for communications include enabling Internet-ready devices (that are not PCs) and offering the scaleability to serve simple to complex applications. Vendors are finding that their customers are considering the fit between all the components in a package, including the RTOS, GUI, and Internet technologies.
Wind River is paying particular attention to the demands of the new Internet devices. According to Wheeler, these "thin" clients are expected to dramatically exceed traditional PCs in requiring Internet access. "As a result, we have to develop and packag key technologies like Java, embedded Web browsers, and servers for building Internet appliances." Skoglund agrees that "The popularization of Java is also important, and RTOS vendors need to be sure to pay attention to it."
With an eye to what's next in the Internet space, Wind River is a contributor to the I2O special interest group (SIG) that is defining and promoting a standard interface for high-performance I/O systems. (As Internet content increases, so does the demand for higher-performance I/O systems.) The company has developed the IxWorks product, a lightweight, scaleable, resource-efficient RTOS based on the company's Wind kernel that provides a single plug-in framework for communicating with all I2O drivers.
Splitting the OS between host and target is another technology trend. In this type of configuration, those parts of a system that do not need to operate in real-time can run on the host. "OSE has been working on enabling the running of a system on both the host and the target. This can be very useful both in the development and deployment of a system," reports Skoglund.
Leroux observes that the technology trends and the movement to communication applications is changing how OEMs are using and selecting an RTOS. "They are looking beyond initial R&D considerations to the longer-term benefits of building quality, maintainability, and flexibility into their products," explains Leroux. "In other words, they're selecting an RTOS based on total product lifecycle and time-to-profit."
What's next
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The communication space will remain a priority for RTOS vendors as they shape their products for the next century. Wind River, for instance, is investing significant R&D efforts in Internet infrastructure components, Internet Server technology like I2O, and Internet client technologies. Also, the company recently created a business unit that is chartered to extend Wind River's reach into higher-value communication platforms for building a variety of network devices.
Enea OSE plans to concentrate on datacommunication and telecommunication applications, developing more protocols and network products that improve reliability. The company is also focusing on broadening its support for a variety of digital signal processors (DSPs) in order to add value to a DSP (or combination CPU/DSP) environment.
QNX is centering its R&D efforts on "total multimedia and Internet solutions for customers building Net-centric client devices, and on high-availability libraries, drivers, and servers for customers building network infrastructure equipment," according to Leroux.
Future additions to the Microsoft Windows CE product include additional protocol stacks. Chouinard reports that the company is "implementing cutting-edge management stacks" and adding features such as HTTP servers.
In all, the primary RTOS vendors are outfitting their products towards the high-growth markets like communications, and creating "total solution" packages. For those of you in need of well-made kernels and tools optimized for your application, you're in luck.
Janine Sullivan is the president of The Write Solution based in Parsippany, NJ. She was formerly the chief editor for Communications Products magazine. She holds a BA from the University of Delaware and an MA from Duquense University. She can be contacted at write@interactive.net
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