无线传感器网络中英文对照外文翻译文献

或在

Zigbee

不可用时，使用

GPRS

网络。

3

在孟加拉国，

< br>在恒河三角洲的几千万人饮用了已被砷严重污染的地下水，

如果被

污染的水量一直持续，

由砷引起的患病率和皮肤癌将大约每年分别增加两百万和 一万

例，由砷引起的癌症的死亡率每年将会大约增加三千例。

我们对于控制砷在地下水中的动态变化是难以完全了解的。

在与 孟加拉国的工程

技术大学和麻省理工学院进行合作中，

我们于< /p>

2006

年

1

月 在靠近达卡的一个水稻地

里部署了一个传感网络，

目的是为了帮 助确认这个假说成立。

一个完整的塔架应该包

含

3

部分完整的传感器（土壤湿度，温度，碳酸盐，钙，硝酸，氯，氧化还原电位 ，

氨氮，

pH

值），每个部署都具有不 同的深度（在地面以下

1

，

1.5

，

2

米），在此基

础上的压力传感器用来监测水的深度。

在干旱地区和半干旱地 区水的短缺和不断增加的对于水资源的消耗已经促进人

们重新再利用被处理过的废水。< /p>

尽管对于水资源的再利用人类收获了很多益处，

但是

已被处理的废水对于人类的健康和环境质量仍然存在着显而易见的危害。

解决 这些危

害需要进行自动的分布式的观测和控制灌溉水量，

查出它 所传输的污染物，

包括暂停

处理的或是还未处理的污染物，胶状 污染物，药物，有机碳，挥发性有机化合物，治

病微生物，

营养 素例如氮或磷。

在加利福尼亚的帕姆代尔，

一个水质再利用现场 是为

测试土壤湿度，

温度和硝酸盐的传感器网络而被用作的试车 台。

此网络集合了两个方

面：第一，确保此环境正在被监测，第 二，提供对水质控制的反馈，从而达到优化水

流量和减少化学物质渗透到地下。

这种现场也可以被用来在对孟加拉国进行部署前对

软件，传感器和硬件的 测试。

3

．传感器共享技术

对于传感器网络数据收集，

即使是最小的传感器资源，

其共享也将让许多人受益。

我们相信以下三种技术方法特别适用于传感器共享：（

1

）从一系列小型传感器大范

围部署到精确仿 真。

（

2

）从密集部署到稀疏部署逐渐 移动冗余传感器（

3

）在一些可

能的地 区缩短部署周期。

在这里，

我们更详细地描述这些场景，

包括我们自己和别人

在执行有关的或支持的算法时的工作的调查。

(1)

精确仿真

4

人类功能的移动性就是通过手动 来模拟一个使用较少传感器的密集部署区。

人们

可以移动一个领 域的一小套传感器，

对密集空间收集数据。

该技术将是只适合于 可持

续发展应用中，所关注的现象变化非常缓慢。

(2)

密集到稀疏部署

一些传感器网络应用需要一个密集映射的环境。

一旦传感器密集部署和细节的 现

象揭示，

我们可以看到它可以捕获足够的资料较少的传感器，

从而释放传感器部署在

其他地方。这里，我们描述适用的工作是 正在进行中的传感器网络社区。

(3)

部署周期短

< br>有些应用程序只需要短时间部署，

因而对传感器的共享是种理想选择。

加拉的部署是一个带有部署周期短的应用例子。

< br>我们要收集数据，

以验证有关昼夜变

化的假设，所以我们 希望数天时间来对数据进行分析。

4

．挑战

许 多挑战性技术的出现，

是为了能够快速部署和移动传感器，

主要 因为迄今为止

的工作主要集中在静态的，长期运行的部署中。

我们已经有了趋于密集化的目标，

降低高密度部署使之稀疏，< /p>

使周期短的部署趋

于平衡，

我们发现以下 三个挑战是最恰当的。

算法必须是具有人机通信功能的，

对于< /p>

人为错误是可以解决的。

对于系统故障必须迅速查明，

进行接收。最后，系统必须迅速做出部署。< /p>

5

．结论

无线传感器网络可视为一种工具，

其对于可持续发展来说具有很好的 潜力。

如果

我们视这种发展的无线传感网络技术为共享资源的话 ，它就可以得到技术社区的帮

助。

为了使无线传感器网络作为一 种共享资源得到落实，

我们确定了三个有希望的技

术方法：精确 仿真，从密集部署到稀疏部署，实施短周期部署。我们讨论了我们的工

作部署，

这些部署已证明了这些技术，

描述了我们的过去和现在需要做哪些工作去 面

对即将出现的重大挑战。

5

Designing Wireless Sensor Networks as a

Shared Resource

for Sustainable Development

Abstract

：

Wireless

sensor

networks

(WSNs)

are

a

relatively

new

and

rapidly

developing

technology;

they

have

a

wide

range

of

applications

including

environmental

monitoring,

agriculture, and public health. Shared technology is a common usa ge model for technology

adoption

in

developing

countries.

WSNs

have

great

potential

to

be

utilized

as

a

shared

resource due to their on-board processing and ad-hoc networking capabilities, however their

deployment as a shared resource requires that the technical

community ?rst address several

challenges. The main challenges include enabling sensor portability

–

the frequent movement

of sensors within and between deployments, and rapidly deployable systems

–

systems that

are quick and simple to ?rst discuss

the feasibility of using sensor net-works as a

shared

resource,

and

then

describe

our

research

in

addressing

the

various

technical

challenges that arise in enabling such senso rportability and rapid deployment. We also outline

our experiences in developing and deploying water quality monitoring wireless sensor networks

in Bangladesh and California.

Key words: WSNs

、

on-board processing

1 Introduction

Wireless Sensor Networks (WSNs), networks of wirelessly connected sensing

and

computational

devices,

hold

tremendous

promise

for

many

areas

of

development

including

public

health,the

environment,

and

agriculture.

A

single

device

has

a

processor,

a

radio, and

several sensors. When

a network of

these

devices is deployed in a ?eld, the

sensing devices measure particular aspects of

the environment. The devices then communicate those measurements by radio to

one another and to more powerful computers for data analysis. In this way, WSNs

6

can

provide

detailed

observations

of

various

phenomena

that

occur

in

the

environment.

WSNs

are

capable

of measuring

diverse

phenomena

such

as

contaminant

levels

in

water,

pollutants

in

the

air,

and

the

?ow

of

water

for

irrigation.

As

an

example

of

a

potential

application,

consider

the

recent

incident

of

contamination

spilling into the Songhua river in China, the main source of drinking water for many

people1.

Determining

rate

of

?ow

and

sometimes

direction

of

the

river

requires

coordination

of

multiple

sampling

points.

Sensors

periodically

taking

samples

at

multiple locations along the river could determine the rate, quantity, and direction of

contaminant ?ow using the distributed sensing

and processing of a wireless sensor

network.

Unfortunately,

the

potential

of

wireless

sensor

net-works

for

sustainable

development2

remains

largely

untapped

while

they

are

designed

primarily

for

relatively

resource-rich

application

contexts.

The

cost

of WSNs is one of

several

major

barriers

that

prevents

them

from

being

leveraged

for

sustainable

development applications. Many components of WSNs are becoming cheaper (e.g.

computing

power),

but

the

sensors

themselves

remain

the

most

expensive

component3.

As

stated

in

[5],

successful

technology-based

international

development projects rely on shared technology due to excessive cost of personal

devices.

However,

most

research

on

sensor

networks

is

based

on

long-term

deployments owned by a single user, a paradigm not conducive for sharing. The

complexity

of

technology

management

is

another

barrier.

We

use

Grameen

telecom as

a

successful

model 4

in

which

the

management and

maintenance of

shared hardware is centralized. We envision a sensor network much in the same

light.

Many sensor network applications are conducive to such a shared model. We

base this statement on the observation that sensors may not be required in a single

location for extended periods of time for reasons including: (1) a phenomenon of

interest may have a slow rate of change, thus a small number of sensors can be

7

moved within a deployment, emulating the density required to suciently capture the

physical

phenomena,

(2)

the

initial

deployment

may

have

been

too

dense,

thus

redundant sensors can be removed, and (3) the duration of the deployment may be

short. We discuss these scenarios in more detail in Section 3.

All of the deployment scenarios mentioned above rest on the assumption that

sensors can be easily deployed and re-deployed. While WSNs have great potential

to be utilized as a shared resource due to their on-board processing and ad- hoc

networking

capabilities,

their

deployment

as

a

shared

resource

requires

that

the

technical

community

?rst

address

several

challenges,

including

enabling

sensor

portability

–

the frequent movement of sensors within and between deployments,

and rapidly deployable systems

–

systems that are quick and simple to deploy. This

leads us to our major challenges in Section 4.

Clearly, the primary issues related to successful technology adoption are the

social, policy, and logistical questions to be answered in order to enable equitable

access and the design of culturally appropriate technology. Our experience, though

relevant, is limited to our technical expertise. These challenges and others should

be formulated more explicitly with the necessary diverse input from communities,

activists, governments and NGOs.

In this paper we focus on justifying the technical feasibility of designing sensor

networks

as

a

shared

technology

(Section

3)

and

describing

the

technical

challenges

that

must

be

addressed

to

enable

WSNs

as

a

shared

technology

(Section 4). We begin by describing our applications in water quality monitoring in

Bangladesh and California (Section 2).

2 WSNs For Water Quality

Wireless

sensor

networks

are

made

up

of

small

computational

devices

connected to various sensors and wireless radios. The devices automatically and

adaptively form ad-hoc networks (temporary point-to-point networks) over wireless

radios

to

make

decisions

based

on

measurements

of

their

environment.

The

8