A framework for interference analysis of heterogeneous radio networks

The increasing use of unlicensed frequency bands for radio communications calls for investigations of the interference between coexisting radio networks. The wide variety of radio interfaces makes such investigations hard to perform. In this paper we present a general framework for the analysis of heterogeneous interfering radio networks, where the networks are modeled with individual properties for the packet types used, transmitted power distributions in time and frequency from the packet transmissions, and with path loss between network nodes. By using closed form expressions for the throughput of the networks, important mechanisms limiting their performance can be investigated. The closed form expressions enable fast and flexible analysis to be performed without extensive computer simulations. To illustrate the use of the framework we analyze an example system of interfering IEEE 802.11b and Bluetooth network

Energy-based throughput analysis of packet radio networks

The increasing use of wireless technology utilizing unlicensed frequency bands calls for more in-depth analysis of interference and coexistence between systems. In this paper a framework is presented for detailed analysis of the performance of coexisting networks in shared frequency bands. The framework allows for multiple packet lengths to be used by the communicating devices and the analysis is performed with respect to the received interfering energy, which in effect leads to a link budget analysis on a packet basis. A system of interfering Bluetooth piconets is analyzed to illustrate the use of the framework and the conceptual difference in basing the analysis on link budgets, rather than on packet collisions. Furthermore, some indications on throughput saturation in the analyzed Bluetooth system are presented

Throughput analysis of strongly interfering slow frequency-hopping wireless networks

We derive an approximation for the throughput of strongly interfering frequency-hopping wireless networks, where packet collisions always result in lost data. A system is defined to consist of a certain number of radio networks, each with an arbitrary number of communicating units, coordinated to communicate without interference. Using the approximation, we estimate upper and lower bounds on system throughput, as well as the number of networks which gives maximum system throughpu

Throughput Analysis of Interfering Packet Radio Networks

In this thesis, a probabilistic framework is presented and used for analysis of the throughput of interfering packet-based radio networks, referred to as packet radio networks (PRNs). Previous research on the performance of PRNs covers a wide variety of systems and aspects in varying levels of detail. However, the work presented in the literature has mostly been limited to fixed packet lengths. The framework presented in this thesis allows for detailed analysis of PRNs using different lengths of the transmitted packets, which is the typical situation in real systems. The framework also allows for analysis of PRNs using slow frequency hopping and different spectral widths and shapes of the transmissions, which enable analysis of heterogeneous systems of interfering networks. An introduction to radio systems and interference is presented along with an overview over previous work on interfering PRNs. An overview of the analytical framework used in this thesis is also presented, including a description of the system model and two methods used for deriving closed form throughput expressions. The first method is based on packet collisions, where two or more packets overlapping in time and frequency result in lost packets and reduced throughput. The second method is based on the amounts of interfering energy received by the network units. Here, a packet is assumed to be lost if the received amount of interfering energy exceeds a given threshold. Assuming that packet collisions always result in lost packets, exact and approximative closed form expressions are derived for both successful packet reception probabilities and throughput of interfering networks. The closed form expressions are used in analyses of interfering slow frequency-hopping networks, illustrating how the relative lengths of packet transmissions can have a great impact on the achievable data rates. Closed form expressions for the throughput of interfering networks based on received interfering energy quantities are also derived. These can be used to analyze heterogeneous systems of interfering networks where different radio interfaces are used by each network, a situation which is becoming increasingly common in shared frequency bands. Finally, the relation between the two methods of analysis is investigated, and in addition, results from calculations are compared with results from measurements on real networks

Energy-based interference analysis of heterogeneous packet radio networks

While the use of radio technology for wireless data communications has increased rapidly, the wide variety of radio interfaces being used has made interference investigations hard to perform. With that in mind, we present a novel approach for analyzing packet radio communications, applicable to interfering heterogeneous networks, which leads to tractable analytical expressions. The core of the approach is an analytical framework modeling each network with individual properties for the packet types and the channel sets used, while taking path loss between all network nodes into account. Furthermore, we present a derivation of closed-form expressions for the throughput of the networks, thus allowing for the investigation of important mechanisms limiting network and system performance. The expressions enable fast and flexible analysis to be performed without extensive computer simulations or measurement campaigns. To illustrate the use of the framework and the strength of the closed-form expressions, we analyze a heterogeneous example system consisting of one IEEE 802.11b network and multiple Bluetooth networks that use multiple packet types. In the analysis, we also take the adjacent channel interference into account when calculating network throughput as functions of the number of interferers in the system

Energy-Based Analysis of Interfering IEEE 802.11b and Bluetooth Networks

The increasing use of wireless technology utilizing unlicensed frequency bands calls for more in-depth analysis of interference and coexistence between systems. In this paper a framework is presented for detailed analysis of the performance of coexisting networks in shared frequency bands. The framework allows for multiple packet lengths to be used by the communicating devices and the analysis is performed with respect to the received interfering energy, which in effect leads to a link budget analysis on a packet basis. A system of interfering Bluetooth piconets is analyzed to illustrate the use of the framework and the conceptual difference in basing the analysis on link budgets, rather than on packet collisions. Furthermore, some indications on throughput saturation in the analyzed Bluetooth system are presented

Analysis of strongly interfering slow frequency-hopping systems

In this report slow frequency-hopping systems are analyzed with respect to the probability of successful transmission of packets, and with respect to the throughput. It is assumed that collisions result in a loss of all information contained in the colliding packets, irrespective of the distance between the units of the system. Units transmit packets of different types with a certain probability, and the packet types can be of different lengths. Two main modes of transmission are treated: synchronous and asynchronous transmission. In the former case, units can only begin transmission of packets at multiples of a common slot time. In the asynchronous case, no such restriction exists. Under the given assumptions, we arrive at analytical expressions for the probability of successful transmission of packets and for the throughput. In addition, approximations of the analytical expressions are given. Finally, two examples are given that show how our system model can be mapped onto existing systems. In the first exampl