Jyrki T. J. Penttinen

The SFN Gain in Non-interfered and Interfered DVB-H Networks

The single frequency network mode (SFN) is one of the benefits of DVB-H network. In addition to the possibility to use only one frequency in given area, the reception of the same contents via two or more radio paths provides with SFN gain which enhances the quality of service whenever the respective sites are located inside the SFN limits. If the same frequency is used outside the theoretical SFN area, the sites that exceed the relative guard distance converts as interfering sources. This paper describes a simulation method for the investigation of the SFN gain in non-interfered network as well as in the environment with SFN interferences. Also simulation results and analysis with the most logical network parameter set is presented.

Performance Model for Orthogonal Sub Channel in Noise-Limited Environment

Orthogonal Sub Channel (OSC) is a voice enhancement for the GSM evolution. It allows in principle a double capacity with the same hardware compared to the previous GSM Half Rate (HR) mode. This paper investigates the effects of OSC on the radio performance as function of the OSC capable handset penetration compared to the GSM HR mode. A set of test cases was carried out in GSM network in order to evaluate the radio performance of OSC in terms of the carrier per noise level. The tests were performed in noise-limited indoor environment, and the quality and received power level distributions were analyzed. As a main achievement, a generic model for estimating the effect of OSC on the GSM radio performance was developed. The model is based on the network statistics and performance indicators of GSM.

Capacity Gain Estimation for Orthogonal Sub Channel

OSC (Orthogonal Sub Channel) is an enhancement for the GSM voice traffic. It provides up to double capacity in the GSM radio interface with the same hardware compared to the previous GSM Half Rate (HR) mode. This paper investigates the effects of the OSC on the capacity utilization compared to the GSM HR as function of the OSC capable handset penetration. The variation of the radio network capacity is studied by taking into account the division of the time slot usage between HR and OSC capable terminals. The results show the achievable capacity gains in terms of reduced time slots and transceiver units with given blocking rate.

Performance of Orthogonal Sub Channel with Dynamic Frequency and Channel Allocation

It has been shown that the performance of GSM can be enhanced by the utilization of OSC (Orthogonal Sub Channel) and Dynamic Frequency and Channel Allocation (DFCA) functionalities. So far, the effect of OSC and DFCA on the radio performance and capacity gain has been investigated separately. This paper investigates the performance enhancement when both of the functionalities are utilized at the same time, which results in the higher hardware efficiency and capacity gains. The studies are based on the analysis of the simulations and performance measurements statistics collected from real networks. A model for estimating the OSC penetration in a DFCA enabled network is proposed.

Prediction model for the GSM Dual Half Rate gain in a noise-limited environment based on field measurements and simulations

The GSM voice capacity can be enhanced by the OSC (Orthogonal Sub Channel) functionality. It allows the sharing of a Half Rate (HR) channel for two separate HR users. OSC makes the pairing of these HR users by dividing the modulation constellation into two separate parts in downlink, and by utilizing the non-correlating training sequences in uplink. OSC thus doubles the offered capacity in those areas where the network conditions allow the pairing. The pairing can be done if the received power level is high enough. In addition, there are quality triggers for the pairing and un-pairing, according to the applied OSC algorithm. This paper investigates the expected OSC gain by taking into account the typical OSC pairing criteria. The effect is analyzed based on the realistic outdoor field measurement data. Furthermore, a model for the OSC performance is developed. This model is utilized as a basis for the simulations that take into account the relevant parameter behavior of the OSC algorithm. The outcome is an estimate of the achievable OSC capacity gain based on the OSC capable handset penetration and network performance statistics, with an indication of optimal OSC parameter values.

MPE-FEC performance in function of the terminal speed in typical DVB-H radio channels

The detailed network planning of DVB-H requires understanding about the regional differences and their effects on the functionality of the system performance. A deep city center contains various radio components whereas rural area normally consists of a single line-of-sight signal resulting differences in the error behavior in the DVB-H reception. In the city area, the terminal velocity is normally limited to pedestrian and relatively slowly moving vehicular speeds. On the other hand, the Doppler shift might be the limit of DVB-H performance in the motorways across rural areas due to the higher velocities. This paper presents a radio interface quality analysis methodology based on the erroneous frames and bit error rates. A selected set of field and laboratory test cases and respective results of the performance analysis is presented. The results can be used as a basis for balancing the MPE-FEC rate and capacity of DVB-H during the related in-depth radio network optimization.

The Simulation of the Interference Levels in Extended DVB-H SFN Areas

The maximum size of the single frequency network (SFN) of DVB-H depends on the guard interval (GI) and FFT mode. The distance limitation between the extreme transmitter sites is thus straightforward to calculate. Nevertheless, there might be need to extend the theoretical SFN areas e.g. due to the lack of frequencies. This paper describes a simulation method for obtaining information about the effect of parameter settings on the error levels caused by the over-sized DVB-H SFN area. The functionality of the method was tested by programming a simulator and analysing the variations of carrier per interference distribution. The results show that the limits can be exceeded e.g. by selecting the antenna height in optimal way and accepting certain increase of the error level that is called SFN error rate (SER) in this analysis.

SFN gain estimations based on frequency response

DVB-H (Digital Video Broadcasting, Handheld) is based on the terrestrial version of DVB, i.e. DVB-T, and it has been designed especially for the moving environment. The performance of the system takes into account the variations of the power levels and bursty interferences of the radio path. DVB-H is adequate especially for the small handsets as the typical terminal screen size requires only a fraction of the bit stream capacity compared to DVB-T which is meant for the fixed reception with the antennas located in rooftop.

DVB-H radiation aspects

The typical radiating power levels of the DVB-H sites are normally between the values used in mobile and television broadcast networks. It is thus important to take into account accordingly the EMC (Electro Magnetic Compatibility) as well as the human exposure limits in the DVB-H transmission facilities. This paper presents a practical method for estimating the safety limits of human exposure and EMC in different DVB-H installation environments. Furthermore, case studies are presented for the most typical environments.