3G Handset and Network Design

The advantage of wireless is that we have added mobility to the user experience. After 20 years of using cellular phones, however, we take mobility for granted and now expect to have the same services available to us in a ... [full story]

We tend to think of copper access as being bandwidth rich, but in practice we become frequency-limited. Attenuation increases rapidly with frequency, which means the distance over which we can travel becomes limited as frequency increases. In practical and economic ... [full story]

Now compare this with a session-switched rich media exchange. As shown in Figure 14.3, in a session-switched exchange, a packet flow is established between two or more users or two or more devices. The job of the application layer software ... [full story]

Traditional Call Management in a Wireless Network The shows a traditional call setup, call maintenance, and call clear-down procedure in a wireless network. The procedure is similar to a wireline network, except the SS7 signaling has to manage interruptions (dropped ... [full story]

We have said that one of the objectives in 3G network design is to deliver wireless/ wireline transparency. The problem is that to deliver performance equivalence, we would need to match wireline throughput, wireline quality, and wireline consistency. Our expectation ... [full story]

From the user’s perspective, the critical measurement is application performance. From the network operator’s perspective, the criteria required is to be able to demonstrate and prove that pre-agreed application performance metrics have been delivered, which requires some form of proof-of-performance ... [full story]

We have to consider the need to deliver end-to-end latency (delay and delay variability guarantees) to meet particular quality of service requirements specified in our users’ service level agreement. To do this, we need to take into account all the ... [full story]

We can reduce delay and delay variability by overprovisioning, but this reduces bandwidth efficiency and increases cost. We can control delay and delay variability by introducing traffic shaping protocols, which means we can determine that some users will have low ... [full story]

Sources of Delay, Error, and Jitter Sensitivity We can qualify and quantify sources of end-to-end delay as follows:  Source encoding introduces delay—typically 20 or 30 ms to source encode an audio or video bit stream. The more complex the ... [full story]

The four classes of traffic in IMT2000 are conversational, streaming, interactive, and background:  Conversational implies a delay of not more than 80 ms.  Streaming implies a delay of not more than 500 ms.  Interactive implies a delay ... [full story]

We have said that traffic consists of five components—voice, image, video, file transfer, and transactions. In the past, we might have built a revenue stream on voice or data, but now we can potentially build five revenue streams, which can ... [full story]

Our six converging industries all have separate standards committees working on hardware and software standardization and content standardization (including, for example, authentication and encryption standards). The Internet potentially provides a uniform set of protocols that can be used to move ... [full story]

We can also look at offered traffic at an industry level. We said earlier that six industries are converging: computer, consumer electronics, IT, wireless, wireline, and TV. As we will see in later chapters, each of these industries has an ... [full story]

At this point we should differentiate admission control and policy control:  Admission control maintains information about the available resources from a network entity.  Policy control checks the administrative entitlement to the requested QoS (which may be for an ... [full story]

You also need to be able to qualify protocol performance. We add traffic shaping protocols to manage the allocation of radio and network resources when demand on those resources at times exceeds supply. Traffic shaping protocols, however, absorb bandwidth, which ... [full story]

You might expect that as traffic streams aggregate together (that is, multiple traffic streams from multiple users), the traffic streams would smooth. However, we have just said this doesn’t happen in the handset, so why should it happen when we ... [full story]

This transition however, needs to deliver transparent cost and performance benefits, and must take into account future changes in the offered traffic mix and offered traffic properties. These changes include a radio bandwidth transition—a change from constant-rate, variable-quality channels to ... [full story]

IP protocols are proposed as a pervasive solution to access management, traffic management, mobility management, and network management. We can use IP protocols to manage access rights to delivery and memory bandwidth, to determine priority access to delivery and server ... [full story]

The Preservation of Traffic Value (Content Value) Consider that content is produced by and for a wide range of devices. The value of the content has to be preserved as it moves into and through the network. Quality degradation introduced ... [full story]

In earlier chapters, we described how bursty bandwidth can put RF components (RF power amplifiers) into compression. Bursty bandwidth can also put ADCs into compression. Bursty bandwidth can also cause buffer overflow in routers, resulting in packet loss (buffer ... [full story]

In our last chapter we looked at the impact of asynchronous traffic on network hardware (antennas, filters, and optical transport). In this chapter, we try and define some of the traffic characteristics and traffic properties and how these characteristics and ... [full story]

Optical components provide access to large quantities of optical bandwidth (several hundred Terahertz). However, bit error rates need to be typically 1 in 1012 or better. This places severe demands on component performance and effectively means that our optical transport ... [full story]

Filters are an important ingredient in radio bandwidth quality�"the Q of the filter has a direct impact on received C/I and transmit energy purity (keeping transmit energy out of other users’ transmit and receive bands). Superconductor filters deliver very substantial ... [full story]

Most present deployment objectives can be met by using conventional passive antennas with a modest amount of reconfigurability—some electrical downtilt, for example. Smart adaptive antenna schemes may become more economically attractive in the future because of the need to selectively ... [full story]

Wavelength-division multiplexing (WDM) was introduced in 1994. WDM is defined as using channel spacing of 3 nanometers (375 GHz). Dense wavelength-division multiplexing (DWDM) is defined as 1 nm or less (<125 GHz). The ITU specifies 100 and 50 GHz channel ... [full story]

Optical transport can be divided into ultra long haul, long haul, and metropolitan.  Ultra long haul is up to 6000 kilometers, typically using a 40 channel × 10 Gbps multiplex.  Long haul is up to 600 km, typically ... [full story]

Just as in the RF domain, we can produce wavelength-selective devices that present a low loss for some wavelengths and a high loss for others by introducing a phase shift in a portion of the light energy. The options are ... [full story]

RF over fiber has been made possible by an enabling technology—linear lasers. In the core network, optical transport bandwidth quantity and quality is improving as new enabling technologies became available, particularly linear optical amplifiers, optical filters, and in the longer ... [full story]

So far in this chapter we have looked at how the characteristics of copper determine the characteristics and quality of the radio signal. We can also take an RF signal and convert it to an optical signal using a linear ... [full story]

Superconductivity filters are based on the principle that resistance to current flow reduces with temperature. Superconductivity filters are made from either thin or thick film deposition processing that promises very good conductivity when cooled to temperatures of 90 K or ... [full story]

The devices just described allow us to multiplex different operators using different RF channels onto shared RF hardware (the antenna). In addition, we need to separate RF channels within the base station transceiver. If a single channel is placed through ... [full story]

Directional couplers are used to combine or split power from or to transmitters and their loads. These may also be referred to as hybrid combiners, splitters, or diplexers. Applications range from printed circuit functions realized in micro strip, to combining ... [full story]