Auto-Configuration Protocols in Mobile Ad Hoc Networks

The TCP/IP protocol allows the different nodes in a network to communicate by associating a different IP address to each node. In wired or wireless networks with infrastructure, we have a server or node acting as such which correctly assigns IP addresses, but in mobile ad hoc networks there is no such centralized entity capable of carrying out this function. Therefore, a protocol is needed to perform the network configuration automatically and in a dynamic way, which will use all nodes in the network (or part thereof) as if they were servers that manage IP addresses. This article reviews the major proposed auto-configuration protocols for mobile ad hoc networks, with particular emphasis on one of the most recent: D2HCP. This work also includes a comparison of auto-configuration protocols for mobile ad hoc networks by specifying the most relevant metrics, such as a guarantee of uniqueness, overhead, latency, dependency on the routing protocol and uniformity

Distributed Dynamic Host Configuration Protocol (D2HCP)

Mobile Ad Hoc Networks (MANETs) are multihop wireless networks of mobile nodes without any fixed or preexisting infrastructure. The topology of these networks can change randomly due to the unpredictable mobility of nodes and their propagation characteristics. In most networks, including MANETs, each node needs a unique identifier to communicate. This work presents a distributed protocol for dynamic node IP address assignment in MANETs. Nodes of a MANET synchronize from time to time to maintain a record of IP address assignments in the entire network and detect any IP address leaks. The proposed stateful autoconfiguration scheme uses the OLSR proactive routing protocol for synchronization and guarantees unique IP addresses under a variety of network conditions, including message losses and network partitioning. Simulation results show that the protocol incurs low latency and communication overhead for IP address assignment

Glucose levels in first 3 days and neurodevelopmental outcome at 1 year in low birth weight infants: A cohort study

Background: Definition of neonatal hypoglycemia is still controversial. Objective: To find the effect of blood glucose (BG) levelsin the first 3 days of life, on developmental outcome at 1 year in low birth weight neonates <2000 g. Methods: A prospective cohortstudy was conducted in tertiary level neonatal intensive care unit and follow-up clinic in south India. Intramural neonates admittedfrom September 2009 to August 2010 were enrolled. Perinatal and neonatal variables were recorded. Respiratory support, fluids,and feeding management were based on the standard protocols. BG was measured within 2 h, then 6 hourly for 72 h by glucometerand BG <50 mg% was analyzed by hexokinase method. Infants were followed until 1 year corrected age and development age(DA) assessed by Developmental Assessment Scales for Indian Infants (DASII). Motor and mental DA at various BG levelswere compared. Composite outcome of motor or mental developmental delay; or cerebral palsy or hearing impairment or visualimpairment was analyzed, and logistic regression analysis was performed. Results: The mean birth weight and gestation of the studygroup (n=129) was 1493 g and 32.5 weeks. The 10th centile of BG in the first 72 h was 51 mg%. BG below 10th centile was seen in60 infants. The mean motor and mental DA of the infants by DASII assessment at 1 year was 11.3 and 11.5 months, respectively.The motor DA and mental DA were significantly higher until 50 mg% lowest BG level, and positive correlation was seen (r=0.26motor, 0.2 mental DA). Mean BG level, the presence of symptoms; number of episodes or small for gestation did not influence theDA. The adjusted odds for poor composite outcome when BG was below 51 mg% is 2.83 (0.65-12.3). Conclusion: Even thoughhigh-risk neonates with BG <51 mg% have a lower motor DA and mental DA at 1 year, than neonates with BG >50 mg%; othermorbidities do determine their composite outcome

The effects of cerebral oximetry in mechanically ventilated newborns: a protocol for the SafeBoosC-IIIv randomised clinical trial

Background The SafeBoosC project aims to test the clinical value of non-invasive cerebral oximetry by near-infrared spectroscopy in newborn infants. The purpose is to establish whether cerebral oximetry can be used to save newborn infants’ lives and brains or not. Newborns contribute heavily to total childhood mortality and neonatal brain damage is the cause of a large part of handicaps such as cerebral palsy. The objective of the SafeBoosC-IIIv trial is to evaluate the benefits and harms of cerebral oximetry added to usual care versus usual care in mechanically ventilated newborns. Methods/design SafeBoosC-IIIv is an investigator-initiated, multinational, randomised, pragmatic phase-III clinical trial. The inclusion criteria will be newborns with a gestational age more than 28 + 0 weeks, postnatal age less than 28 days, predicted to require mechanical ventilation for at least 24 h, and prior informed consent from the parents or deferred consent or absence of opt-out. The exclusion criteria will be no available cerebral oximeter, suspicion of or confirmed brain injury or disorder, or congenital heart disease likely to require surgery. A total of 3000 participants will be randomised in 60 neonatal intensive care units from 16 countries, in a 1:1 allocation ratio to cerebral oximetry versus usual care. Participants in the cerebral oximetry group will undergo cerebral oximetry monitoring during mechanical ventilation in the neonatal intensive care unit for as long as deemed useful by the treating physician or until 28 days of life. The participants in the cerebral oximetry group will be treated according to the SafeBoosC treatment guideline. Participants in the usual care group will not receive cerebral oximetry and will receive usual care. We use two co-primary outcomes: (1) a composite of death from any cause or moderate to severe neurodevelopmental disability at 2 years of corrected age and (2) the non-verbal cognitive score of the Parent Report of Children’s Abilities-Revised (PARCA-R) at 2 years of corrected age. Discussion There is need for a randomised clinical trial to evaluate cerebral oximetry added to usual care versus usual care in mechanically ventilated newborns. Trial registration The protocol is registered at www.clinicaltrials.gov (NCT05907317; registered 18 June 2023)

Distributed Wireless Channel Allocation in Networks with Mobile Base Stations

In traditional cellular systems with fixed base stations the channel reuse pattern is static and deterministic. When the cell layout is dynamic, due to the mobility of base stations, the cluster of cells within co-channel interference range changes with time. Consequently, the channel reuse pattern is highly dynamic. Moreover, base stations also need wireless channels to communicate amongst themselves. A communication session between a pair of nodes may have to switch channels due to the movement of other nodes into the neighborhood. Hence, there is a need for new wireless channel allocation algorithms for virtual cellular systems with mobile base stations. In this paper, principles of mutual exclusion pertaining to distributed computing systems are employed to develop such an algorithm. The inter-base station wireless links are referred to as backbone links while the base station-mobile node links are referred to as short-hop links. The proposed algorithm is distributed, dynamic and d..

MANETconf: Configuration of Hosts in a Mobile Ad Hoc Network

A mobile ad hoc network (MANET) is a multi-hop wireless network capable of autonomous operation. The mobility of MANET nodes can lead to frequent and unpredictable topology changes. Most MANET literature assumes that network related information of a node (such as its IP address, netmask, etc.) is configured statically, prior to the node joining the MANET. However, not all nodes have IP addresses permanently assigned to them. Such nodes rely on a centralized server and use a dynamic host configuration protocol, like DHCP [1], to acquire an IP address. Such a solution cannot be employed in MANETs due to the unavailability of any centralized DHCP server. In this paper, we first present a survey of possible solutions approaches, and discuss their limitations. Then, we present a distributed dynamic host configuration protocol designed to configure nodes in a MANET. We show that the proposed protocol works correctly and does not have the limitations of earlier approaches. Finally, we evaluate the performance of the solution through simulation experiments, and conclude with a discussion of related security issues

MANETconf: Configuration of Hosts in a Mobile

A mobile ad hoc network (MANET) is a multi-hop wireless network capable of autonomous operation. The mobility of MANET nodes can lead to frequent and unpredictable topology changes. Most MANET literature assumes that network related information of a node (such as its IP address, netmask, etc.) is configured statically, prior to the node joining the MANET. However, not all nodes have IP addresses permanently assigned to them. Such nodes rely on a centralized server and use a dynamic host configuration protocol, like DHCP [1], to acquire an IP address. Such a solution cannot be employed in MANETs due to the unavailability of any centralized DHCP server. In this paper, we first present a survey of possible solutions approaches, and discuss their limitations. Then, we present a distributed dynamic host configuration protocol designed to configure nodes in a MANET. We show that the proposed protocol works correctly and does not have the limitations of earlier approaches. Finally, we evaluate the performance of the solution through simulation experiments, and conclude with a discussion of related security issues