footer.html

<ion-tabs>
  <ion-tab [root]="tab1" tabTitle="Trips" tabIcon="car"></ion-tab>
  <ion-tab [root]="tab2" tabTitle="My Trips" tabIcon="bicycle"></ion-tab>
  <ion-tab [root]="tab3"  [rootParams]="profileParams" (ionSelect)="getProfile()" tabTitle="Profile" tabIcon="contact"></ion-tab>
  <ion-tab [root]="tab4" tabTitle="Settings" tabIcon="settings"></ion-tab>
</ion-tabs>

Profile.ts

import { Component, OnInit } from '@angular/core';
import { NavController, NavParams, LoadingController } from 'ionic-angular';
import { Storage } from '@ionic/storage';
import * as localforage from "localforage";
import { ProfileServices } from '../../providers/profile.services';

@Component({
  template: '<div>test</div>',
  providers: [ProfileServices]
})
export class Profile {    
    public user: any;
    public userProfile: any;
    
    constructor(public navCtrl: NavController, public params: NavParams, public storage: Storage,	private profile:ProfileServices){
        console.log("Passed params", params.data); //Object empty
        console.log("Passed params", params.get("dto"));//undefined
        console.log("Passed params", params.data.dto);//undefined     
    }
}

Tabs.ts

import { Component, ViewChild } from '@angular/core';
import { NavController, NavParams, LoadingController } from 'ionic-angular';
import { IntroPage } from '../intro/intro';
import { LoginPage } from '../login/login';
import { Profile } from '../profile/profile';
import { Privacy } from '../privacy/privacy';
import { Settings } from '../settings/settings';
import { Storage } from '@ionic/storage';
import { ProfileServices } from '../../providers/profile.services';

@Component({
  selector: 'page-footer',
  templateUrl: 'footer.html',
  providers: [ProfileServices]
})
export class Footer {

  //Tabss
  tab1: any = Trips;
  tab2: any = MyTrips;
  tab3: any = Profile;
  tab4: any = Settings;

  //Parameters
  profileParams: any;

  constructor(public navCtrl: NavController, public params: NavParams, public storage: Storage, public loading:LoadingController, private profileService: ProfileServices){    
    this.storage.set('user', JSON.stringify( this.params.get("user") ) ).then(() => {
      console.log('Name has been set');
    });
  }  
  ionViewDidLoad() {
    this.storage.get('user').then((user) => {
      console.log('User footer'+user);
    });    
  }
  getProfile(){
    this.profileParams = {dta:"jkjk",dto:"kkjm",nombre:9};
  }
}

In the documentation of ionic 2 show how to pass parameters to the page of a tab that works with an attribute in the contructor as shown here:

But not working, But does not work with events? , The idea is that when I do (ionSelect) in the tab update the value of the variable in [rootParams] but it does not.