Take The Trivia Questions Quiz On Radio Resource Management!

When the power level of a base station exceeds the Ptx_threshold or the received power level at the base station exceeds the Prx_threshold, the overload control mechanism of the LC (Load Control) and PS (Packet Scheduler) will be triggered. This mechanism aims to prevent network congestion and maintain the quality of service. As a result, the bitrate of the non-real-time (NRT) bearers will be decreased and some bearers may be dropped to alleviate the overload situation. Therefore, the statement is true.

Micro diversity refers to the phenomenon where a Node B (base station) receives multiple signal paths from a single cell or from different sector cells in a sectorized Node B. This is a result of multi-path propagation, where signals bounce off obstacles and take different paths before reaching the base station. Therefore, the statement is true.

Inter-System Handovers (ISHO) are indeed of the traditional type, similar to those used in GSM. This type of handover is also known as hard handover, as it involves breaking the old connection and establishing a new connection instead of maintaining simultaneous connections. Therefore, the given answer "True" is correct.

When the mobile is switched on but there is no RRC connection with the network, it is considered to be in idle mode. In this mode, the mobile is listening to one base station and is ready to establish a connection or waiting to be paged. This means that the mobile is not actively engaged in any communication or data transfer, but is still powered on and able to receive incoming requests or signals from the network.

When the UE is switched on, it checks if the radio environment matches the one it has stored in memory. If it does, the UE informs the VLR that it is attached again and can handle transactions. If the radio environment does not match, the UE performs a location area update. Therefore, the statement "When the UE is switched on, it first checks whether the radio environment matches the one it has in memory" is true.

A URA (Utran Registration Area) is a group of UMTS (Universal Mobile Telecommunications System) cells that are combined together. This combination helps to avoid excessive cell-changing procedures on the edges of cells. This means that when a mobile device moves from one cell to another within the URA, it doesn't need to perform a cell change, which can improve the efficiency and performance of the network. Therefore, the statement that "A URA consists of one or more UMTS cells that are combined in order to avoid a surplus of cell-changing procedures on the edge of cells" is true.

Power control is indeed extremely essential in mobile networks for the reasons mentioned. The fact that mobiles transmit simultaneously in time and the use of only one frequency in UTRAN increases the likelihood of interference. Inaccurate power control can further exacerbate interference, leading to a decrease in network capacity. Therefore, the statement "Power Control (PC) is extremely essential" is true.

The explanation for the given correct answer is that when planning a WCDMA network, it is indeed important to define the acceptable interference level. This is because the interference level can affect the network's ability to function correctly. The planning based value for the acceptable interference level is used to set practical limits for the Uu interface capacity, which is the interface between the user equipment (UE) and the network. Therefore, the statement that the acceptable interference level is a basic criteria for planning a WCDMA network is true.

Macro diversity is a technique used in wireless communication systems where a user equipment (UE) is connected to multiple cells simultaneously. This helps to improve the quality of the radio link and ensure better connectivity. The RNC (Radio Network Controller) uses Outer Loop Power Control to maintain the quality of the radio link. This control mechanism adjusts the transmission power of the UE based on the observed Bit Error Rate (BER) and Frame Error Rate (FER) to achieve the target quality. Therefore, the statement that the UE is simultaneously attached to the network through more than one cell and the RNC uses Outer Loop Power Control to maintain the quality of the radio link is true.

The explanation for the correct answer is that traffic in a cell can indeed be categorized by priority based on the type of traffic, such as conversational, streaming, interactive, and background. These categories can further be divided into real-time (RT) and non-real-time (NRT) traffic. Therefore, the statement is true.

The macro diversity point in UMTS is located at the RNC (Radio Network Controller). The RNC is responsible for controlling and managing multiple Node Bs (base stations) within a UMTS network. It coordinates the handover process between different Node Bs to ensure seamless connectivity and optimize network performance. The RNC plays a crucial role in implementing macro diversity, which is a technique used to improve signal quality and reduce interference by combining signals from multiple antennas or base stations. Therefore, the correct answer is RNC.

The RNC (Radio Network Controller) is responsible for keeping track of the mobiles within the URAs (Uplink Radio Access) and informing the Core Network when a subscriber changes their Location Area (LA) and/or Routing Area (RA). This means that the statement is correct, as the RNC plays a crucial role in managing and tracking mobile devices within the network.

When a cell update or routing area update occurs, the mobile device temporarily loses its connection to the network. During this time, it is unable to receive or send data. In order to prevent data loss, the SGSN (Serving GPRS Support Node) can buffer the data until the connection is reestablished. This ensures that no data is lost during the update process. Therefore, the statement is true.

Soft handover is a feature in cellular networks where a mobile device is simultaneously connected to multiple base stations. This allows for seamless handover between cells, resulting in improved call quality and coverage. In order for soft handover to occur, the source and target cells must have the same frequency. This is because the mobile device needs to be able to receive and transmit signals on the same frequency in order to maintain a continuous connection during the handover process. Therefore, the statement that the source and target cell of the soft handover should have the same frequency is true.

The RRC-connected state is indeed a prerequisite for the exchange of user data and signaling between the UE (User Equipment) and the network. This state is established when the UE successfully completes the RRC (Radio Resource Control) connection procedure with the network. In this state, the UE is able to transmit and receive data, as well as exchange signaling messages with the network. Without being in the RRC-connected state, the UE would not be able to establish a connection with the network and therefore cannot exchange data or signaling. Hence, the statement is true.

A frequency and a code characterize a physical layer because in communication systems, the physical layer is responsible for transmitting and receiving signals over a physical medium. The frequency refers to the specific range of electromagnetic waves used for transmission, while the code refers to the modulation scheme or encoding technique used to represent the data. These two characteristics are fundamental in defining the physical layer and its ability to transmit data reliably and efficiently.

When a UE changes cells between different routing areas, it performs a RA Update. A Routing Area (RA) is a group of cells that are managed by a specific Mobility Management Entity (MME). When the UE moves from one RA to another, it needs to inform the network about its new location. This is done through a RA Update procedure, where the UE sends a signaling message to the MME to update its location information. This allows the network to route incoming calls and data to the UE's new location.

Soft handover is a feature in cellular networks where a mobile device is connected to multiple base stations simultaneously. This allows for seamless communication as the device can switch between the base stations without interruption. In soft handover, the base stations can belong to different Node Bs, which are responsible for managing the base stations, but they may not necessarily belong to the same Radio Network Controller (RNC), which is responsible for controlling and managing the base stations. Therefore, the given statement is true.

The given answer is true because the parameters mentioned (downlink centre frequency, downlink bandwidth, downlink scrambling code or scrambling code group for the CPICH, and reference time difference for the UTRA cell) are indeed the ones that enable the UE (User Equipment) to measure the neighboring UTRA FDD (Universal Terrestrial Radio Access Frequency Division Duplex) cell. These parameters provide the necessary information for the UE to detect and measure the signal strength and quality of the neighboring UTRA FDD cell.

When a UE (User Equipment) makes a Location Registration, it sends two numbers: LAI (Location Area Identity) and TMSI (Temporary Mobile Subscriber Identity). LAI is used to identify the location area of the UE, while TMSI is a temporary identifier assigned to the UE by the network. These numbers are sent during the registration process to ensure that the network can identify and authenticate the UE correctly. The other options, AUTN and TMSI, and LAI and AUTH, are incorrect as they do not represent the numbers sent during a Location Registration.

The explanation for the given correct answer is that wideband switching in the RNC (Radio Network Controller) does indeed make the element structure of the RNC different from the element structure of the BSC (Base Station Controller) in GSM BSS (GSM Base Station Subsystem) during implementation. Wideband switching refers to the ability to transmit a large amount of data over a wide frequency range, and it allows for more efficient and faster communication in the RNC compared to the BSC. This difference in element structure is a result of the technological advancements and improvements in the RNC compared to the older GSM BSS system.

The MAC layer is responsible for scheduling and mapping logical channel data onto the transport channels provided by the physical layer. This means that it determines how the data will be transmitted over the physical channels, ensuring efficient and reliable communication. Therefore, the statement is true.

An RA (Radio Access) is a network element in a cellular network that provides wireless communication between user devices and the core network. It is responsible for managing the radio resources and handling the communication protocols. An RA can consist of one or more URA (Uplink Radio Access) components, which are responsible for transmitting data from the user device to the network. Therefore, the statement "An RA is composed of one or more URA" is true, as an RA can have multiple URA components working together to provide efficient and reliable wireless communication.

When a subscriber performs a soft handover, it means that they are transferring from one RNC (Radio Network Controller) to another. In this scenario, if the scrambling code in the UL (Uplink) is already being used by another person in the new RNC, the handover is refused. This is because the scrambling code is used to differentiate between different users in the same cell, and it cannot be shared by multiple users simultaneously. Therefore, the SRNC (Serving RNC) must allocate a new scrambling code to the subscriber in order to complete the handover successfully.

The statement suggests that the planning of scrambling code groups for different frequency carriers can be done independently. This means that the selection and assignment of scrambling codes for each carrier frequency can be done separately without any dependency or interference. Therefore, the statement is true.

The micro diversity point in UMTS is located at the Node B. The Node B is responsible for transmitting and receiving signals between the base station and the mobile devices. The micro diversity technique is used to improve the signal quality and reduce interference by utilizing multiple antennas at the Node B. This allows for better coverage and higher data rates in UMTS networks.

In closed loop power control, the Node commands the UE to adjust its transmission power based on the received SIR (Signal-to-Interference Ratio) estimated by the Node B. If the received SIR is low, indicating high interference, the Node commands the UE to increase its transmission power. Conversely, if the received SIR is high, indicating low interference, the Node commands the UE to decrease its transmission power. This control loop helps to maintain a consistent and optimal power level for the UE, ensuring efficient and reliable communication in the network.

The Load Control function of the RNC is both preventive and corrective in terms of overload control. This means that it not only takes measures to prevent overload situations from occurring in the first place but also takes corrective actions if an overload does occur. This ensures that the network remains stable and can handle the traffic efficiently.

Soft HO stands for Soft Handover. In a soft handover, the UE (User Equipment) is connected to at least two Node Bs (Base Stations) simultaneously. This allows for seamless handover between different base stations, resulting in improved call quality and coverage. The RNC (Radio Network Controller) selects the signal to be transported to the Core Network (CN), either frame by frame for speech or in smaller blocks for data. Therefore, the statement "In soft HO, the UE is connected to at least two Node Bs at the same time" is true.

In this scenario, the correct answer is multi-path propagation. Multi-path propagation refers to the phenomenon where a signal sent through a radio path is reflected off various surfaces such as ground, water, and buildings. These reflections create multiple copies of the original signal at the receiving end, leading to interference and signal degradation. This can cause signal fading, distortion, and errors in the received signal.

MAC stands for Media Access Control, which is a sublayer of the Data Link Layer in the OSI model. Its main function is to control access to the physical medium and handle the transmission of data between devices. One of the functions of MAC is multiplexing, which involves combining multiple logical channels into the same transport channel. This allows for efficient use of the available bandwidth by sharing the same physical channel among different data streams. Therefore, the correct answer is "Multiplexing of logical channels into same transport channels."

In UMTS.

When the cell load exceeds 70%, it means that the cell is operating at a high capacity and is close to being overloaded. This high load can lead to increased interference within the cell, making it difficult to control and manage the quality of service for the users. Therefore, the statement is true.

In Cell_FACH (Forward Access Channel) mode, the mobile device is in an idle state but is still connected to the network. It is able to receive paging messages and send small amounts of data. This mode is used for applications such as web browsing or sending/receiving emails, where the data transmission is not continuous but still requires a relatively low latency. The network can also perform handovers as the mobile device moves from one cell to another in this mode.

In PS connections, when the UE changes cell within a routing area in Ready Mode, it performs a cell update and cell reselection. This process is similar to a handover in UMTS or GSM for PS connections. Therefore, the statement "True" is correct.

Inter-frequency handovers refer to the process of transferring a mobile device's connection from one frequency band to another. Hard handovers involve a complete break in the connection before switching to the new frequency. Since all inter-frequency handovers involve a complete break in the connection, they are considered hard handovers. Therefore, the statement that all inter-frequency handovers are hard handovers is true.

Intra-System HO refers to handover within the same system or network, in this case, the WCDMA radio network. This means that the handover process involves transferring a call or data session from one base station to another within the same WCDMA network. Inter-System HO, on the other hand, would involve transferring the call or session between different systems or networks, such as from a WCDMA network to a GSM network.

In the UMTS system, the inter-system handover is enabled in the Slotted Mode. This mode allows the UE (User Equipment) to use the Uu interface in a slotted manner, where the contents of the Uu interface frame are compressed to create a time window. This time window allows the UE to peek and decode the GSM BCCH (Broadcast Control Channel) information. In order for this decoding to be successful, both the WCDMA RAN (Radio Access Network) and GSM BSS (Base Station Subsystem) need to send the identity information of the other system on the BCCH and BCH (Broadcast Channel) channels. This enables the UE to properly perform the decoding and facilitate inter-system handover.

Layer 2 processing.

The given formula calculates the interference margin based on the load factor. The load factor represents the utilization of a system or network, ranging from 0 to 1. The formula uses logarithmic calculations to determine the interference margin, which is a measure of the system's ability to handle interference. Therefore, the statement "True" indicates that the formula is correct.

In Release 3, the packet scheduler's actions are determined by the load control function, which means that the packet scheduler adjusts its behavior based on the current load of the cell. This allows the packet scheduler to fill any gaps between the real-time (RT) traffic and the load target of the cell, ensuring that the cell's resources are efficiently utilized. Therefore, the statement "True" is correct.

SIR (Signal-to-Interference Ratio) is a measure of the quality of a wireless signal, specifically the ratio of the desired signal power to the interference power. It is also known as Interference Margin because it represents the amount of interference that can be tolerated before the signal quality deteriorates. The higher the SIR, the better the signal quality and the lower the interference. Therefore, SIR has a direct relationship with the cell load, as a higher cell load can lead to more interference and a lower SIR.

In Cell_DCH (Cell Dedicated Channel) mode/state, a dedicated channel is provided to the subscriber. This means that the UE (User Equipment) has a dedicated connection to the network, allowing for faster and more efficient communication. In this state, the UE is also sending measurement reports to the network, which helps the system control the dedicated bearer (the specific channel being used for communication) and perform handovers (transferring the connection from one cell to another).

Channelization codes are used in wireless communication systems to separate different users or signals. During a connection, it is possible for the channelization codes to change. This can happen due to various reasons such as interference, network congestion, or optimization of the system. Therefore, the statement "Channelization codes could change during a connection" is true.

From the perspective of the User Equipment (UE) to the network connection point of view, when the RRC (Radio Resource Control) changes its state from idle to connected, it means that the UE is transitioning from a state where it is not actively communicating with the network to a state where it is connected and ready to exchange data with the network. This change in state allows the UE to establish a connection with the network and start sending and receiving data. Therefore, the statement "True" is correct.

Only idle and connected states.

The Resource Manager function in the RNC is responsible for the allocation of bearer. It manages and allocates network resources such as bandwidth and channels to establish and maintain the communication channels between the RNC and the connected devices. The Resource Manager ensures efficient utilization of resources and allocates them based on the network's capacity and the requirements of the connected devices.

Soft and softer handover refers to the process of transferring a mobile connection from one base station to another without interrupting the call. This type of handover increases system capacity because it allows for better utilization of available resources. By seamlessly transferring the connection between base stations, the network can accommodate more users and provide a smoother and more reliable service. Therefore, the statement "Soft and softer handover increases system capacity" is true.

The statement is true because when the total transmit power (Ptx_target + Ptx_offset) exceeds a certain threshold, preventive control of load control (LC) and admission control (AC) is activated. This means that new bearers are not admitted, and the power saving (PS) feature decreases the bitrate of non-real-time (NRT) bearers to reduce the overall power consumption.

An LA (Logical Address) is indeed composed of one or more RA (Relative Addresses). This means that a logical address can consist of multiple relative addresses, which are used to identify specific locations within the logical address space. The inclusion of "one or more" implies that an LA can have multiple RAs associated with it, further supporting the statement's correctness.