For OEMs, selecting the right technology can make it easier to reach the small and medium-sized business market with new devices for converged voice, video, and data services.
When you ask five friends if they want to go for some ice cream, it's likely that five or more different flavors will pop into their heads as they contemplate their answer. Small businesses are similar to ice cream except there are many more than the classic 31 flavors. The classic definition of a small-medium business (SMB) is 8 to 100 employees at a single location. Obviously, significant differences in the services and equipment are required at both ends of this spectrum. A small business may be the sole location for an enterprise. In this case, all communication capabilities will be required at this location.
Another enterprise may actually be quite large but be composed of many branch offices that fit the “small business” definition. For this enterprise, the communication requirements of each branch could vary greatly. However, it's clear that they all want to better manage their telecommunication infrastructure and provide the better value-add services to their customers that an Internet protocol (IP) network can provide. In addition, they need simplicity in installation and maintenance.
Although the application mix that a small business needs to support its business is changing, at a high level the requirement is for voice, data, and video service. Small businesses, like large enterprises, also want to take advantage of new low-cost voice-over-IP (VoIP) services. This can be accommodated with the addition of IP phones or an IP-PBX (IP private branch exchange), but traditional analog services, such as fax and security alarms, aren't going away and need to be integrated into the overall service offerings to the SMB. Thus the voice system needs to accommodate both new generation IP devices as well as traditional fax and modem devices.
Video, particularly video surveillance, is increasingly becoming a requirement. Often, specific video events need to be detected, recorded in high resolution, and archived for insurance or legal purposes. Data support, particularly providing connectivity with customers for sales and support, is almost a given. Electronic transactions often need to be archived. The complexity of installing and operating these systems is beyond the capability of most small businesses. For this reason, many now outsource these services to a network operator or value added reseller.
Equipment makers addressing the needs of small business must provide many device “flavors.” In the small business market, one size definitely does not fit all. All of the applications described above use digital signal processing (DSP) because they convert the real world of voice and video to a digital representation for compression, transmission, and storage analysis in real time.
Although some of the general-purpose processors offer “DSP enhancements,” they have architecture deficiencies that aren't suitable for real-time applications. In addition, DSPs are uniquely scalable. Scalability is a key capability for OEMs (original equipment manufacturers) addressing the SMB market. Remember, they need systems capable of supporting between 8 and 100 users. This range is a wide variance for a single processor that needs to be efficient at both ends of the scale.
DSPs are often available in families, with the smallest “family member” able to process a handful of channels of voice or video and the largest capable of hundreds of simultaneous channels. Configurations between the extremes are often handled by a mid-sized DSP or by combining several of the smaller DSPs into a DSP “farm.” OEMs taking advantage of this approach will benefit from a common code base and development environment that scales across the entire SMB requirement. The result will be lower development cost and reduced time to develop derivative products. SMB products may be physically integrated with voice, data, and video support or a system of interoperating devices. They may be installed and managed by a service provider or by the SMB staff. In all cases, manageability is a key requirement.
Among SMBs, the trend is growing in favor of “all-in-one” communications plans that combine core voice, data, and video services. For service providers, this trend is creating interest in customer-premises platforms for service delivery over a variety of network types, including DSL, cable, fiber, and wireless. Service providers and their customers want a platform that supports simple installation and maintenance, avoids the expense of skilled IT personnel and enables a low total cost of ownership.
Many network-equipment vendors are developing single-platform solutions to converge communications services for SMBs, such as integrated network access switches and “office-in-a-box” devices. At the foundation of these platforms are the capabilities and design of DSP technology. For OEMs, choosing DSP technology can make a considerable difference for the types of services enabled, product development requirements, and platform flexibility and scalability.
A key factor for these new, converged-network access platforms is support for both voice and video on the same DSP, with a large number of channels for each traffic type. When voice and video support are available on a single DSP, OEMs can realize the following benefits:
• Reduced chip size and cost, for lower-cost user devices.
• Scalability within the user device as the customer's business grows and uses more voice and video channels.
• A simpler development platform because a single DSP core supports both voice and video. A unified, scalable development architecture also allows OEMs to share development efforts across multiple products.
• Ability to mix and match voice and video channels on the same DSP for very small systems, or to dedicate the DSP to either voice or video traffic for high-density applications.
• Ability to connect IP and analog phones, fax machines, and analog modems.
• Process video feeds and connect video cameras within a single network device.
• Support for new, value-added applications such as biometric fingerprint readers or speech recognition as used in the SMB auto attendant.
Silicon solutions and their associated software should support the design of products ranging from IP phones to network-access platforms to carrier-class switches. These systems use DSPs to execute software that encodes and decodes voice and performs the signal processing required to facilitate the transmission of voice between various networks. To deliver toll-quality and high-definition voice and enhance the quality of all services, OEMs should be able to optimize these solutions for area, cost per channel, power consumption, and architecture according to the needs of each application.
As shown in Figure 1, the DSP often communicates with an external network or host processor in the system. Because many OEMs have existing development investments in a host-processing environment, a DSP that's compatible with any host processor is essential. In some applications, where scalability isn't desired, the DSP supplier should offer a choice of standalone DSPs for voice processing and integrated DSPs that combine voice and host processing on one device.
A new concept, the office-in-a-box platform , combines multiple SMB communications in one network-access device. Today, these solutions provide voice functionality such as:
• Phone: Connections and power for wired IP and analog phones as well as a digital PBX, whether these devices are targeted at the low-cost, mid-tier, or high-end markets. In the future, telephony support will extend to wireless and fixed-mobile convergence user devices.
• VoIP gateway: Connections for access lines and voice trunks. Also supports foreign-exchange station/foreign-exchange offices, fax and modem devices, and a full range of voice codecs.
• IP-PBX application: Provides software-based call management with voice mail and applications such as specialized call routing and call attendant.
Moving forward, office-in-a-box will include:
• Router: Enterprise-class data routing with multiple, scalable Ethernet ports.
• Firewall/unified threat management: Security for data, voice, and video streams.
• Wireless LAN access point and WAN modem: Multiple types of wireless LAN and WAN access could be added as cards in the device. WAN types supported include DSL, cable, and passive optical network (PON). At some point, the requirement to support WiMAX may emerge.
• Video surveillance: Support for video surveillance cards and convergence of the video streams with voice and data applications. SMB customers will also want the option to store video files locally or send video streams over the network to a central monitoring station. This will be done selectively based on analysis of a real-time video feed that detects an event that needs to be recorded. This capability requires video-codec conversions to obtain optimal bandwidth use over the network.
• Storage: Support for networked storage or customer-provided equipment (CPE) storage devices for voice mail and video files.
• Management: An integrated framework for remotely managing devices and quality-of-service for voice and video traffic.
The service integration offered by an office-in-a-box solution depends on a single-DSP system design. The single DSP provides the necessary integration of voice, video, and data processing. Figure 2 shows a typical system design using an integrated DSP. With this system design, an office-in-a-box device can support the features listed in Table 1.
As OEMs and ODMs (original design manufacturers) begin their SMB product design, they must carefully consider whether they're designing plain vanilla single-function devices or integrated solutions that scale between applications and are designed to meet the varied needs of the end customer. These decisions will have a material impact on which DSP technology they select and how that selection will make it easier to reach SMB markets with converged devices.
Ravi Kodavarti is a product manager in Texas Instruments' VoIP group. He is responsible for product definition and direction for a family of VoIP solutions for the SMB segment. Kodavarti holds a BE from Karnataka Regional Engineering College, India, an MS from Texas A&M University, and an MBA from Northwestern University's Kellogg School of Management. He can be reached at .
Tom Flanagan is the director of technical strategy for TI's DSP Systems group. Flanagan received his bachelor's degree of science from James Madison University.